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5742 lines
221 KiB
5742 lines
221 KiB
# module pyparsing.py |
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# |
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# Copyright (c) 2003-2018 Paul T. McGuire |
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# |
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# Permission is hereby granted, free of charge, to any person obtaining |
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# a copy of this software and associated documentation files (the |
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# "Software"), to deal in the Software without restriction, including |
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# without limitation the rights to use, copy, modify, merge, publish, |
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# distribute, sublicense, and/or sell copies of the Software, and to |
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# permit persons to whom the Software is furnished to do so, subject to |
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# the following conditions: |
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# |
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# The above copyright notice and this permission notice shall be |
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# included in all copies or substantial portions of the Software. |
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# |
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# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, |
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# EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF |
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# MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. |
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# IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY |
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# CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, |
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# TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE |
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# SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. |
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# |
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__doc__ = \ |
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""" |
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pyparsing module - Classes and methods to define and execute parsing grammars |
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============================================================================= |
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|
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The pyparsing module is an alternative approach to creating and executing simple grammars, |
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vs. the traditional lex/yacc approach, or the use of regular expressions. With pyparsing, you |
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don't need to learn a new syntax for defining grammars or matching expressions - the parsing module |
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provides a library of classes that you use to construct the grammar directly in Python. |
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|
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Here is a program to parse "Hello, World!" (or any greeting of the form |
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C{"<salutation>, <addressee>!"}), built up using L{Word}, L{Literal}, and L{And} elements |
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(L{'+'<ParserElement.__add__>} operator gives L{And} expressions, strings are auto-converted to |
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L{Literal} expressions):: |
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from pyparsing import Word, alphas |
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|
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# define grammar of a greeting |
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greet = Word(alphas) + "," + Word(alphas) + "!" |
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|
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hello = "Hello, World!" |
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print (hello, "->", greet.parseString(hello)) |
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|
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The program outputs the following:: |
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Hello, World! -> ['Hello', ',', 'World', '!'] |
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The Python representation of the grammar is quite readable, owing to the self-explanatory |
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class names, and the use of '+', '|' and '^' operators. |
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|
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The L{ParseResults} object returned from L{ParserElement.parseString<ParserElement.parseString>} can be accessed as a nested list, a dictionary, or an |
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object with named attributes. |
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The pyparsing module handles some of the problems that are typically vexing when writing text parsers: |
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- extra or missing whitespace (the above program will also handle "Hello,World!", "Hello , World !", etc.) |
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- quoted strings |
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- embedded comments |
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Getting Started - |
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----------------- |
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Visit the classes L{ParserElement} and L{ParseResults} to see the base classes that most other pyparsing |
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classes inherit from. Use the docstrings for examples of how to: |
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- construct literal match expressions from L{Literal} and L{CaselessLiteral} classes |
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- construct character word-group expressions using the L{Word} class |
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- see how to create repetitive expressions using L{ZeroOrMore} and L{OneOrMore} classes |
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- use L{'+'<And>}, L{'|'<MatchFirst>}, L{'^'<Or>}, and L{'&'<Each>} operators to combine simple expressions into more complex ones |
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- associate names with your parsed results using L{ParserElement.setResultsName} |
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- find some helpful expression short-cuts like L{delimitedList} and L{oneOf} |
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- find more useful common expressions in the L{pyparsing_common} namespace class |
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""" |
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__version__ = "2.2.1" |
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__versionTime__ = "18 Sep 2018 00:49 UTC" |
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__author__ = "Paul McGuire <ptmcg@users.sourceforge.net>" |
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import string |
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from weakref import ref as wkref |
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import copy |
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import sys |
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import warnings |
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import re |
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import sre_constants |
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import collections |
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import pprint |
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import traceback |
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import types |
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from datetime import datetime |
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|
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try: |
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from _thread import RLock |
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except ImportError: |
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from threading import RLock |
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|
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try: |
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# Python 3 |
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from collections.abc import Iterable |
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from collections.abc import MutableMapping |
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except ImportError: |
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# Python 2.7 |
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from collections import Iterable |
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from collections import MutableMapping |
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|
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try: |
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from collections import OrderedDict as _OrderedDict |
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except ImportError: |
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try: |
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from ordereddict import OrderedDict as _OrderedDict |
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except ImportError: |
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_OrderedDict = None |
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|
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#~ sys.stderr.write( "testing pyparsing module, version %s, %s\n" % (__version__,__versionTime__ ) ) |
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__all__ = [ |
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'And', 'CaselessKeyword', 'CaselessLiteral', 'CharsNotIn', 'Combine', 'Dict', 'Each', 'Empty', |
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'FollowedBy', 'Forward', 'GoToColumn', 'Group', 'Keyword', 'LineEnd', 'LineStart', 'Literal', |
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'MatchFirst', 'NoMatch', 'NotAny', 'OneOrMore', 'OnlyOnce', 'Optional', 'Or', |
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'ParseBaseException', 'ParseElementEnhance', 'ParseException', 'ParseExpression', 'ParseFatalException', |
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'ParseResults', 'ParseSyntaxException', 'ParserElement', 'QuotedString', 'RecursiveGrammarException', |
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'Regex', 'SkipTo', 'StringEnd', 'StringStart', 'Suppress', 'Token', 'TokenConverter', |
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'White', 'Word', 'WordEnd', 'WordStart', 'ZeroOrMore', |
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'alphanums', 'alphas', 'alphas8bit', 'anyCloseTag', 'anyOpenTag', 'cStyleComment', 'col', |
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'commaSeparatedList', 'commonHTMLEntity', 'countedArray', 'cppStyleComment', 'dblQuotedString', |
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'dblSlashComment', 'delimitedList', 'dictOf', 'downcaseTokens', 'empty', 'hexnums', |
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'htmlComment', 'javaStyleComment', 'line', 'lineEnd', 'lineStart', 'lineno', |
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'makeHTMLTags', 'makeXMLTags', 'matchOnlyAtCol', 'matchPreviousExpr', 'matchPreviousLiteral', |
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'nestedExpr', 'nullDebugAction', 'nums', 'oneOf', 'opAssoc', 'operatorPrecedence', 'printables', |
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'punc8bit', 'pythonStyleComment', 'quotedString', 'removeQuotes', 'replaceHTMLEntity', |
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'replaceWith', 'restOfLine', 'sglQuotedString', 'srange', 'stringEnd', |
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'stringStart', 'traceParseAction', 'unicodeString', 'upcaseTokens', 'withAttribute', |
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'indentedBlock', 'originalTextFor', 'ungroup', 'infixNotation','locatedExpr', 'withClass', |
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'CloseMatch', 'tokenMap', 'pyparsing_common', |
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] |
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system_version = tuple(sys.version_info)[:3] |
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PY_3 = system_version[0] == 3 |
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if PY_3: |
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_MAX_INT = sys.maxsize |
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basestring = str |
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unichr = chr |
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_ustr = str |
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# build list of single arg builtins, that can be used as parse actions |
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singleArgBuiltins = [sum, len, sorted, reversed, list, tuple, set, any, all, min, max] |
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else: |
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_MAX_INT = sys.maxint |
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range = xrange |
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|
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def _ustr(obj): |
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"""Drop-in replacement for str(obj) that tries to be Unicode friendly. It first tries |
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str(obj). If that fails with a UnicodeEncodeError, then it tries unicode(obj). It |
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then < returns the unicode object | encodes it with the default encoding | ... >. |
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""" |
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if isinstance(obj,unicode): |
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return obj |
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try: |
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# If this works, then _ustr(obj) has the same behaviour as str(obj), so |
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# it won't break any existing code. |
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return str(obj) |
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|
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except UnicodeEncodeError: |
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# Else encode it |
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ret = unicode(obj).encode(sys.getdefaultencoding(), 'xmlcharrefreplace') |
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xmlcharref = Regex(r'&#\d+;') |
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xmlcharref.setParseAction(lambda t: '\\u' + hex(int(t[0][2:-1]))[2:]) |
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return xmlcharref.transformString(ret) |
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|
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# build list of single arg builtins, tolerant of Python version, that can be used as parse actions |
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singleArgBuiltins = [] |
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import __builtin__ |
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for fname in "sum len sorted reversed list tuple set any all min max".split(): |
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try: |
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singleArgBuiltins.append(getattr(__builtin__,fname)) |
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except AttributeError: |
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continue |
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_generatorType = type((y for y in range(1))) |
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def _xml_escape(data): |
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"""Escape &, <, >, ", ', etc. in a string of data.""" |
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# ampersand must be replaced first |
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from_symbols = '&><"\'' |
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to_symbols = ('&'+s+';' for s in "amp gt lt quot apos".split()) |
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for from_,to_ in zip(from_symbols, to_symbols): |
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data = data.replace(from_, to_) |
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return data |
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class _Constants(object): |
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pass |
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alphas = string.ascii_uppercase + string.ascii_lowercase |
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nums = "0123456789" |
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hexnums = nums + "ABCDEFabcdef" |
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alphanums = alphas + nums |
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_bslash = chr(92) |
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printables = "".join(c for c in string.printable if c not in string.whitespace) |
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|
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class ParseBaseException(Exception): |
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"""base exception class for all parsing runtime exceptions""" |
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# Performance tuning: we construct a *lot* of these, so keep this |
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# constructor as small and fast as possible |
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def __init__( self, pstr, loc=0, msg=None, elem=None ): |
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self.loc = loc |
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if msg is None: |
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self.msg = pstr |
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self.pstr = "" |
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else: |
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self.msg = msg |
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self.pstr = pstr |
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self.parserElement = elem |
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self.args = (pstr, loc, msg) |
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@classmethod |
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def _from_exception(cls, pe): |
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""" |
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internal factory method to simplify creating one type of ParseException |
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from another - avoids having __init__ signature conflicts among subclasses |
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""" |
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return cls(pe.pstr, pe.loc, pe.msg, pe.parserElement) |
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|
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def __getattr__( self, aname ): |
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"""supported attributes by name are: |
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- lineno - returns the line number of the exception text |
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- col - returns the column number of the exception text |
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- line - returns the line containing the exception text |
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""" |
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if( aname == "lineno" ): |
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return lineno( self.loc, self.pstr ) |
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elif( aname in ("col", "column") ): |
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return col( self.loc, self.pstr ) |
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elif( aname == "line" ): |
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return line( self.loc, self.pstr ) |
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else: |
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raise AttributeError(aname) |
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def __str__( self ): |
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return "%s (at char %d), (line:%d, col:%d)" % \ |
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( self.msg, self.loc, self.lineno, self.column ) |
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def __repr__( self ): |
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return _ustr(self) |
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def markInputline( self, markerString = ">!<" ): |
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"""Extracts the exception line from the input string, and marks |
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the location of the exception with a special symbol. |
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""" |
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line_str = self.line |
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line_column = self.column - 1 |
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if markerString: |
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line_str = "".join((line_str[:line_column], |
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markerString, line_str[line_column:])) |
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return line_str.strip() |
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def __dir__(self): |
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return "lineno col line".split() + dir(type(self)) |
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|
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class ParseException(ParseBaseException): |
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""" |
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Exception thrown when parse expressions don't match class; |
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supported attributes by name are: |
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- lineno - returns the line number of the exception text |
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- col - returns the column number of the exception text |
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- line - returns the line containing the exception text |
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Example:: |
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try: |
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Word(nums).setName("integer").parseString("ABC") |
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except ParseException as pe: |
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print(pe) |
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print("column: {}".format(pe.col)) |
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prints:: |
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Expected integer (at char 0), (line:1, col:1) |
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column: 1 |
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""" |
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pass |
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class ParseFatalException(ParseBaseException): |
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"""user-throwable exception thrown when inconsistent parse content |
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is found; stops all parsing immediately""" |
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pass |
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class ParseSyntaxException(ParseFatalException): |
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"""just like L{ParseFatalException}, but thrown internally when an |
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L{ErrorStop<And._ErrorStop>} ('-' operator) indicates that parsing is to stop |
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immediately because an unbacktrackable syntax error has been found""" |
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pass |
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#~ class ReparseException(ParseBaseException): |
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#~ """Experimental class - parse actions can raise this exception to cause |
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#~ pyparsing to reparse the input string: |
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#~ - with a modified input string, and/or |
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#~ - with a modified start location |
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#~ Set the values of the ReparseException in the constructor, and raise the |
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#~ exception in a parse action to cause pyparsing to use the new string/location. |
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#~ Setting the values as None causes no change to be made. |
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#~ """ |
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#~ def __init_( self, newstring, restartLoc ): |
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#~ self.newParseText = newstring |
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#~ self.reparseLoc = restartLoc |
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|
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class RecursiveGrammarException(Exception): |
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"""exception thrown by L{ParserElement.validate} if the grammar could be improperly recursive""" |
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def __init__( self, parseElementList ): |
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self.parseElementTrace = parseElementList |
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|
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def __str__( self ): |
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return "RecursiveGrammarException: %s" % self.parseElementTrace |
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|
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class _ParseResultsWithOffset(object): |
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def __init__(self,p1,p2): |
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self.tup = (p1,p2) |
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def __getitem__(self,i): |
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return self.tup[i] |
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def __repr__(self): |
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return repr(self.tup[0]) |
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def setOffset(self,i): |
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self.tup = (self.tup[0],i) |
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|
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class ParseResults(object): |
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""" |
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Structured parse results, to provide multiple means of access to the parsed data: |
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- as a list (C{len(results)}) |
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- by list index (C{results[0], results[1]}, etc.) |
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- by attribute (C{results.<resultsName>} - see L{ParserElement.setResultsName}) |
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|
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Example:: |
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integer = Word(nums) |
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date_str = (integer.setResultsName("year") + '/' |
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+ integer.setResultsName("month") + '/' |
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+ integer.setResultsName("day")) |
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# equivalent form: |
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# date_str = integer("year") + '/' + integer("month") + '/' + integer("day") |
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|
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# parseString returns a ParseResults object |
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result = date_str.parseString("1999/12/31") |
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|
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def test(s, fn=repr): |
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print("%s -> %s" % (s, fn(eval(s)))) |
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test("list(result)") |
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test("result[0]") |
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test("result['month']") |
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test("result.day") |
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test("'month' in result") |
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test("'minutes' in result") |
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test("result.dump()", str) |
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prints:: |
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list(result) -> ['1999', '/', '12', '/', '31'] |
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result[0] -> '1999' |
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result['month'] -> '12' |
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result.day -> '31' |
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'month' in result -> True |
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'minutes' in result -> False |
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result.dump() -> ['1999', '/', '12', '/', '31'] |
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- day: 31 |
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- month: 12 |
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- year: 1999 |
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""" |
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def __new__(cls, toklist=None, name=None, asList=True, modal=True ): |
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if isinstance(toklist, cls): |
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return toklist |
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retobj = object.__new__(cls) |
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retobj.__doinit = True |
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return retobj |
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|
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# Performance tuning: we construct a *lot* of these, so keep this |
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# constructor as small and fast as possible |
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def __init__( self, toklist=None, name=None, asList=True, modal=True, isinstance=isinstance ): |
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if self.__doinit: |
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self.__doinit = False |
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self.__name = None |
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self.__parent = None |
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self.__accumNames = {} |
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self.__asList = asList |
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self.__modal = modal |
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if toklist is None: |
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toklist = [] |
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if isinstance(toklist, list): |
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self.__toklist = toklist[:] |
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elif isinstance(toklist, _generatorType): |
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self.__toklist = list(toklist) |
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else: |
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self.__toklist = [toklist] |
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self.__tokdict = dict() |
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|
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if name is not None and name: |
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if not modal: |
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self.__accumNames[name] = 0 |
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if isinstance(name,int): |
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name = _ustr(name) # will always return a str, but use _ustr for consistency |
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self.__name = name |
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if not (isinstance(toklist, (type(None), basestring, list)) and toklist in (None,'',[])): |
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if isinstance(toklist,basestring): |
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toklist = [ toklist ] |
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if asList: |
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if isinstance(toklist,ParseResults): |
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self[name] = _ParseResultsWithOffset(toklist.copy(),0) |
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else: |
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self[name] = _ParseResultsWithOffset(ParseResults(toklist[0]),0) |
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self[name].__name = name |
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else: |
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try: |
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self[name] = toklist[0] |
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except (KeyError,TypeError,IndexError): |
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self[name] = toklist |
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|
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def __getitem__( self, i ): |
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if isinstance( i, (int,slice) ): |
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return self.__toklist[i] |
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else: |
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if i not in self.__accumNames: |
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return self.__tokdict[i][-1][0] |
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else: |
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return ParseResults([ v[0] for v in self.__tokdict[i] ]) |
|
|
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def __setitem__( self, k, v, isinstance=isinstance ): |
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if isinstance(v,_ParseResultsWithOffset): |
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self.__tokdict[k] = self.__tokdict.get(k,list()) + [v] |
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sub = v[0] |
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elif isinstance(k,(int,slice)): |
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self.__toklist[k] = v |
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sub = v |
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else: |
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self.__tokdict[k] = self.__tokdict.get(k,list()) + [_ParseResultsWithOffset(v,0)] |
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sub = v |
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if isinstance(sub,ParseResults): |
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sub.__parent = wkref(self) |
|
|
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def __delitem__( self, i ): |
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if isinstance(i,(int,slice)): |
|
mylen = len( self.__toklist ) |
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del self.__toklist[i] |
|
|
|
# convert int to slice |
|
if isinstance(i, int): |
|
if i < 0: |
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i += mylen |
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i = slice(i, i+1) |
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# get removed indices |
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removed = list(range(*i.indices(mylen))) |
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removed.reverse() |
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# fixup indices in token dictionary |
|
for name,occurrences in self.__tokdict.items(): |
|
for j in removed: |
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for k, (value, position) in enumerate(occurrences): |
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occurrences[k] = _ParseResultsWithOffset(value, position - (position > j)) |
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else: |
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del self.__tokdict[i] |
|
|
|
def __contains__( self, k ): |
|
return k in self.__tokdict |
|
|
|
def __len__( self ): return len( self.__toklist ) |
|
def __bool__(self): return ( not not self.__toklist ) |
|
__nonzero__ = __bool__ |
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def __iter__( self ): return iter( self.__toklist ) |
|
def __reversed__( self ): return iter( self.__toklist[::-1] ) |
|
def _iterkeys( self ): |
|
if hasattr(self.__tokdict, "iterkeys"): |
|
return self.__tokdict.iterkeys() |
|
else: |
|
return iter(self.__tokdict) |
|
|
|
def _itervalues( self ): |
|
return (self[k] for k in self._iterkeys()) |
|
|
|
def _iteritems( self ): |
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return ((k, self[k]) for k in self._iterkeys()) |
|
|
|
if PY_3: |
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keys = _iterkeys |
|
"""Returns an iterator of all named result keys (Python 3.x only).""" |
|
|
|
values = _itervalues |
|
"""Returns an iterator of all named result values (Python 3.x only).""" |
|
|
|
items = _iteritems |
|
"""Returns an iterator of all named result key-value tuples (Python 3.x only).""" |
|
|
|
else: |
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iterkeys = _iterkeys |
|
"""Returns an iterator of all named result keys (Python 2.x only).""" |
|
|
|
itervalues = _itervalues |
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"""Returns an iterator of all named result values (Python 2.x only).""" |
|
|
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iteritems = _iteritems |
|
"""Returns an iterator of all named result key-value tuples (Python 2.x only).""" |
|
|
|
def keys( self ): |
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"""Returns all named result keys (as a list in Python 2.x, as an iterator in Python 3.x).""" |
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return list(self.iterkeys()) |
|
|
|
def values( self ): |
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"""Returns all named result values (as a list in Python 2.x, as an iterator in Python 3.x).""" |
|
return list(self.itervalues()) |
|
|
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def items( self ): |
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"""Returns all named result key-values (as a list of tuples in Python 2.x, as an iterator in Python 3.x).""" |
|
return list(self.iteritems()) |
|
|
|
def haskeys( self ): |
|
"""Since keys() returns an iterator, this method is helpful in bypassing |
|
code that looks for the existence of any defined results names.""" |
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return bool(self.__tokdict) |
|
|
|
def pop( self, *args, **kwargs): |
|
""" |
|
Removes and returns item at specified index (default=C{last}). |
|
Supports both C{list} and C{dict} semantics for C{pop()}. If passed no |
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argument or an integer argument, it will use C{list} semantics |
|
and pop tokens from the list of parsed tokens. If passed a |
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non-integer argument (most likely a string), it will use C{dict} |
|
semantics and pop the corresponding value from any defined |
|
results names. A second default return value argument is |
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supported, just as in C{dict.pop()}. |
|
|
|
Example:: |
|
def remove_first(tokens): |
|
tokens.pop(0) |
|
print(OneOrMore(Word(nums)).parseString("0 123 321")) # -> ['0', '123', '321'] |
|
print(OneOrMore(Word(nums)).addParseAction(remove_first).parseString("0 123 321")) # -> ['123', '321'] |
|
|
|
label = Word(alphas) |
|
patt = label("LABEL") + OneOrMore(Word(nums)) |
|
print(patt.parseString("AAB 123 321").dump()) |
|
|
|
# Use pop() in a parse action to remove named result (note that corresponding value is not |
|
# removed from list form of results) |
|
def remove_LABEL(tokens): |
|
tokens.pop("LABEL") |
|
return tokens |
|
patt.addParseAction(remove_LABEL) |
|
print(patt.parseString("AAB 123 321").dump()) |
|
prints:: |
|
['AAB', '123', '321'] |
|
- LABEL: AAB |
|
|
|
['AAB', '123', '321'] |
|
""" |
|
if not args: |
|
args = [-1] |
|
for k,v in kwargs.items(): |
|
if k == 'default': |
|
args = (args[0], v) |
|
else: |
|
raise TypeError("pop() got an unexpected keyword argument '%s'" % k) |
|
if (isinstance(args[0], int) or |
|
len(args) == 1 or |
|
args[0] in self): |
|
index = args[0] |
|
ret = self[index] |
|
del self[index] |
|
return ret |
|
else: |
|
defaultvalue = args[1] |
|
return defaultvalue |
|
|
|
def get(self, key, defaultValue=None): |
|
""" |
|
Returns named result matching the given key, or if there is no |
|
such name, then returns the given C{defaultValue} or C{None} if no |
|
C{defaultValue} is specified. |
|
|
|
Similar to C{dict.get()}. |
|
|
|
Example:: |
|
integer = Word(nums) |
|
date_str = integer("year") + '/' + integer("month") + '/' + integer("day") |
|
|
|
result = date_str.parseString("1999/12/31") |
|
print(result.get("year")) # -> '1999' |
|
print(result.get("hour", "not specified")) # -> 'not specified' |
|
print(result.get("hour")) # -> None |
|
""" |
|
if key in self: |
|
return self[key] |
|
else: |
|
return defaultValue |
|
|
|
def insert( self, index, insStr ): |
|
""" |
|
Inserts new element at location index in the list of parsed tokens. |
|
|
|
Similar to C{list.insert()}. |
|
|
|
Example:: |
|
print(OneOrMore(Word(nums)).parseString("0 123 321")) # -> ['0', '123', '321'] |
|
|
|
# use a parse action to insert the parse location in the front of the parsed results |
|
def insert_locn(locn, tokens): |
|
tokens.insert(0, locn) |
|
print(OneOrMore(Word(nums)).addParseAction(insert_locn).parseString("0 123 321")) # -> [0, '0', '123', '321'] |
|
""" |
|
self.__toklist.insert(index, insStr) |
|
# fixup indices in token dictionary |
|
for name,occurrences in self.__tokdict.items(): |
|
for k, (value, position) in enumerate(occurrences): |
|
occurrences[k] = _ParseResultsWithOffset(value, position + (position > index)) |
|
|
|
def append( self, item ): |
|
""" |
|
Add single element to end of ParseResults list of elements. |
|
|
|
Example:: |
|
print(OneOrMore(Word(nums)).parseString("0 123 321")) # -> ['0', '123', '321'] |
|
|
|
# use a parse action to compute the sum of the parsed integers, and add it to the end |
|
def append_sum(tokens): |
|
tokens.append(sum(map(int, tokens))) |
|
print(OneOrMore(Word(nums)).addParseAction(append_sum).parseString("0 123 321")) # -> ['0', '123', '321', 444] |
|
""" |
|
self.__toklist.append(item) |
|
|
|
def extend( self, itemseq ): |
|
""" |
|
Add sequence of elements to end of ParseResults list of elements. |
|
|
|
Example:: |
|
patt = OneOrMore(Word(alphas)) |
|
|
|
# use a parse action to append the reverse of the matched strings, to make a palindrome |
|
def make_palindrome(tokens): |
|
tokens.extend(reversed([t[::-1] for t in tokens])) |
|
return ''.join(tokens) |
|
print(patt.addParseAction(make_palindrome).parseString("lskdj sdlkjf lksd")) # -> 'lskdjsdlkjflksddsklfjkldsjdksl' |
|
""" |
|
if isinstance(itemseq, ParseResults): |
|
self += itemseq |
|
else: |
|
self.__toklist.extend(itemseq) |
|
|
|
def clear( self ): |
|
""" |
|
Clear all elements and results names. |
|
""" |
|
del self.__toklist[:] |
|
self.__tokdict.clear() |
|
|
|
def __getattr__( self, name ): |
|
try: |
|
return self[name] |
|
except KeyError: |
|
return "" |
|
|
|
if name in self.__tokdict: |
|
if name not in self.__accumNames: |
|
return self.__tokdict[name][-1][0] |
|
else: |
|
return ParseResults([ v[0] for v in self.__tokdict[name] ]) |
|
else: |
|
return "" |
|
|
|
def __add__( self, other ): |
|
ret = self.copy() |
|
ret += other |
|
return ret |
|
|
|
def __iadd__( self, other ): |
|
if other.__tokdict: |
|
offset = len(self.__toklist) |
|
addoffset = lambda a: offset if a<0 else a+offset |
|
otheritems = other.__tokdict.items() |
|
otherdictitems = [(k, _ParseResultsWithOffset(v[0],addoffset(v[1])) ) |
|
for (k,vlist) in otheritems for v in vlist] |
|
for k,v in otherdictitems: |
|
self[k] = v |
|
if isinstance(v[0],ParseResults): |
|
v[0].__parent = wkref(self) |
|
|
|
self.__toklist += other.__toklist |
|
self.__accumNames.update( other.__accumNames ) |
|
return self |
|
|
|
def __radd__(self, other): |
|
if isinstance(other,int) and other == 0: |
|
# useful for merging many ParseResults using sum() builtin |
|
return self.copy() |
|
else: |
|
# this may raise a TypeError - so be it |
|
return other + self |
|
|
|
def __repr__( self ): |
|
return "(%s, %s)" % ( repr( self.__toklist ), repr( self.__tokdict ) ) |
|
|
|
def __str__( self ): |
|
return '[' + ', '.join(_ustr(i) if isinstance(i, ParseResults) else repr(i) for i in self.__toklist) + ']' |
|
|
|
def _asStringList( self, sep='' ): |
|
out = [] |
|
for item in self.__toklist: |
|
if out and sep: |
|
out.append(sep) |
|
if isinstance( item, ParseResults ): |
|
out += item._asStringList() |
|
else: |
|
out.append( _ustr(item) ) |
|
return out |
|
|
|
def asList( self ): |
|
""" |
|
Returns the parse results as a nested list of matching tokens, all converted to strings. |
|
|
|
Example:: |
|
patt = OneOrMore(Word(alphas)) |
|
result = patt.parseString("sldkj lsdkj sldkj") |
|
# even though the result prints in string-like form, it is actually a pyparsing ParseResults |
|
print(type(result), result) # -> <class 'pyparsing.ParseResults'> ['sldkj', 'lsdkj', 'sldkj'] |
|
|
|
# Use asList() to create an actual list |
|
result_list = result.asList() |
|
print(type(result_list), result_list) # -> <class 'list'> ['sldkj', 'lsdkj', 'sldkj'] |
|
""" |
|
return [res.asList() if isinstance(res,ParseResults) else res for res in self.__toklist] |
|
|
|
def asDict( self ): |
|
""" |
|
Returns the named parse results as a nested dictionary. |
|
|
|
Example:: |
|
integer = Word(nums) |
|
date_str = integer("year") + '/' + integer("month") + '/' + integer("day") |
|
|
|
result = date_str.parseString('12/31/1999') |
|
print(type(result), repr(result)) # -> <class 'pyparsing.ParseResults'> (['12', '/', '31', '/', '1999'], {'day': [('1999', 4)], 'year': [('12', 0)], 'month': [('31', 2)]}) |
|
|
|
result_dict = result.asDict() |
|
print(type(result_dict), repr(result_dict)) # -> <class 'dict'> {'day': '1999', 'year': '12', 'month': '31'} |
|
|
|
# even though a ParseResults supports dict-like access, sometime you just need to have a dict |
|
import json |
|
print(json.dumps(result)) # -> Exception: TypeError: ... is not JSON serializable |
|
print(json.dumps(result.asDict())) # -> {"month": "31", "day": "1999", "year": "12"} |
|
""" |
|
if PY_3: |
|
item_fn = self.items |
|
else: |
|
item_fn = self.iteritems |
|
|
|
def toItem(obj): |
|
if isinstance(obj, ParseResults): |
|
if obj.haskeys(): |
|
return obj.asDict() |
|
else: |
|
return [toItem(v) for v in obj] |
|
else: |
|
return obj |
|
|
|
return dict((k,toItem(v)) for k,v in item_fn()) |
|
|
|
def copy( self ): |
|
""" |
|
Returns a new copy of a C{ParseResults} object. |
|
""" |
|
ret = ParseResults( self.__toklist ) |
|
ret.__tokdict = self.__tokdict.copy() |
|
ret.__parent = self.__parent |
|
ret.__accumNames.update( self.__accumNames ) |
|
ret.__name = self.__name |
|
return ret |
|
|
|
def asXML( self, doctag=None, namedItemsOnly=False, indent="", formatted=True ): |
|
""" |
|
(Deprecated) Returns the parse results as XML. Tags are created for tokens and lists that have defined results names. |
|
""" |
|
nl = "\n" |
|
out = [] |
|
namedItems = dict((v[1],k) for (k,vlist) in self.__tokdict.items() |
|
for v in vlist) |
|
nextLevelIndent = indent + " " |
|
|
|
# collapse out indents if formatting is not desired |
|
if not formatted: |
|
indent = "" |
|
nextLevelIndent = "" |
|
nl = "" |
|
|
|
selfTag = None |
|
if doctag is not None: |
|
selfTag = doctag |
|
else: |
|
if self.__name: |
|
selfTag = self.__name |
|
|
|
if not selfTag: |
|
if namedItemsOnly: |
|
return "" |
|
else: |
|
selfTag = "ITEM" |
|
|
|
out += [ nl, indent, "<", selfTag, ">" ] |
|
|
|
for i,res in enumerate(self.__toklist): |
|
if isinstance(res,ParseResults): |
|
if i in namedItems: |
|
out += [ res.asXML(namedItems[i], |
|
namedItemsOnly and doctag is None, |
|
nextLevelIndent, |
|
formatted)] |
|
else: |
|
out += [ res.asXML(None, |
|
namedItemsOnly and doctag is None, |
|
nextLevelIndent, |
|
formatted)] |
|
else: |
|
# individual token, see if there is a name for it |
|
resTag = None |
|
if i in namedItems: |
|
resTag = namedItems[i] |
|
if not resTag: |
|
if namedItemsOnly: |
|
continue |
|
else: |
|
resTag = "ITEM" |
|
xmlBodyText = _xml_escape(_ustr(res)) |
|
out += [ nl, nextLevelIndent, "<", resTag, ">", |
|
xmlBodyText, |
|
"</", resTag, ">" ] |
|
|
|
out += [ nl, indent, "</", selfTag, ">" ] |
|
return "".join(out) |
|
|
|
def __lookup(self,sub): |
|
for k,vlist in self.__tokdict.items(): |
|
for v,loc in vlist: |
|
if sub is v: |
|
return k |
|
return None |
|
|
|
def getName(self): |
|
r""" |
|
Returns the results name for this token expression. Useful when several |
|
different expressions might match at a particular location. |
|
|
|
Example:: |
|
integer = Word(nums) |
|
ssn_expr = Regex(r"\d\d\d-\d\d-\d\d\d\d") |
|
house_number_expr = Suppress('#') + Word(nums, alphanums) |
|
user_data = (Group(house_number_expr)("house_number") |
|
| Group(ssn_expr)("ssn") |
|
| Group(integer)("age")) |
|
user_info = OneOrMore(user_data) |
|
|
|
result = user_info.parseString("22 111-22-3333 #221B") |
|
for item in result: |
|
print(item.getName(), ':', item[0]) |
|
prints:: |
|
age : 22 |
|
ssn : 111-22-3333 |
|
house_number : 221B |
|
""" |
|
if self.__name: |
|
return self.__name |
|
elif self.__parent: |
|
par = self.__parent() |
|
if par: |
|
return par.__lookup(self) |
|
else: |
|
return None |
|
elif (len(self) == 1 and |
|
len(self.__tokdict) == 1 and |
|
next(iter(self.__tokdict.values()))[0][1] in (0,-1)): |
|
return next(iter(self.__tokdict.keys())) |
|
else: |
|
return None |
|
|
|
def dump(self, indent='', depth=0, full=True): |
|
""" |
|
Diagnostic method for listing out the contents of a C{ParseResults}. |
|
Accepts an optional C{indent} argument so that this string can be embedded |
|
in a nested display of other data. |
|
|
|
Example:: |
|
integer = Word(nums) |
|
date_str = integer("year") + '/' + integer("month") + '/' + integer("day") |
|
|
|
result = date_str.parseString('12/31/1999') |
|
print(result.dump()) |
|
prints:: |
|
['12', '/', '31', '/', '1999'] |
|
- day: 1999 |
|
- month: 31 |
|
- year: 12 |
|
""" |
|
out = [] |
|
NL = '\n' |
|
out.append( indent+_ustr(self.asList()) ) |
|
if full: |
|
if self.haskeys(): |
|
items = sorted((str(k), v) for k,v in self.items()) |
|
for k,v in items: |
|
if out: |
|
out.append(NL) |
|
out.append( "%s%s- %s: " % (indent,(' '*depth), k) ) |
|
if isinstance(v,ParseResults): |
|
if v: |
|
out.append( v.dump(indent,depth+1) ) |
|
else: |
|
out.append(_ustr(v)) |
|
else: |
|
out.append(repr(v)) |
|
elif any(isinstance(vv,ParseResults) for vv in self): |
|
v = self |
|
for i,vv in enumerate(v): |
|
if isinstance(vv,ParseResults): |
|
out.append("\n%s%s[%d]:\n%s%s%s" % (indent,(' '*(depth)),i,indent,(' '*(depth+1)),vv.dump(indent,depth+1) )) |
|
else: |
|
out.append("\n%s%s[%d]:\n%s%s%s" % (indent,(' '*(depth)),i,indent,(' '*(depth+1)),_ustr(vv))) |
|
|
|
return "".join(out) |
|
|
|
def pprint(self, *args, **kwargs): |
|
""" |
|
Pretty-printer for parsed results as a list, using the C{pprint} module. |
|
Accepts additional positional or keyword args as defined for the |
|
C{pprint.pprint} method. (U{http://docs.python.org/3/library/pprint.html#pprint.pprint}) |
|
|
|
Example:: |
|
ident = Word(alphas, alphanums) |
|
num = Word(nums) |
|
func = Forward() |
|
term = ident | num | Group('(' + func + ')') |
|
func <<= ident + Group(Optional(delimitedList(term))) |
|
result = func.parseString("fna a,b,(fnb c,d,200),100") |
|
result.pprint(width=40) |
|
prints:: |
|
['fna', |
|
['a', |
|
'b', |
|
['(', 'fnb', ['c', 'd', '200'], ')'], |
|
'100']] |
|
""" |
|
pprint.pprint(self.asList(), *args, **kwargs) |
|
|
|
# add support for pickle protocol |
|
def __getstate__(self): |
|
return ( self.__toklist, |
|
( self.__tokdict.copy(), |
|
self.__parent is not None and self.__parent() or None, |
|
self.__accumNames, |
|
self.__name ) ) |
|
|
|
def __setstate__(self,state): |
|
self.__toklist = state[0] |
|
(self.__tokdict, |
|
par, |
|
inAccumNames, |
|
self.__name) = state[1] |
|
self.__accumNames = {} |
|
self.__accumNames.update(inAccumNames) |
|
if par is not None: |
|
self.__parent = wkref(par) |
|
else: |
|
self.__parent = None |
|
|
|
def __getnewargs__(self): |
|
return self.__toklist, self.__name, self.__asList, self.__modal |
|
|
|
def __dir__(self): |
|
return (dir(type(self)) + list(self.keys())) |
|
|
|
MutableMapping.register(ParseResults) |
|
|
|
def col (loc,strg): |
|
"""Returns current column within a string, counting newlines as line separators. |
|
The first column is number 1. |
|
|
|
Note: the default parsing behavior is to expand tabs in the input string |
|
before starting the parsing process. See L{I{ParserElement.parseString}<ParserElement.parseString>} for more information |
|
on parsing strings containing C{<TAB>}s, and suggested methods to maintain a |
|
consistent view of the parsed string, the parse location, and line and column |
|
positions within the parsed string. |
|
""" |
|
s = strg |
|
return 1 if 0<loc<len(s) and s[loc-1] == '\n' else loc - s.rfind("\n", 0, loc) |
|
|
|
def lineno(loc,strg): |
|
"""Returns current line number within a string, counting newlines as line separators. |
|
The first line is number 1. |
|
|
|
Note: the default parsing behavior is to expand tabs in the input string |
|
before starting the parsing process. See L{I{ParserElement.parseString}<ParserElement.parseString>} for more information |
|
on parsing strings containing C{<TAB>}s, and suggested methods to maintain a |
|
consistent view of the parsed string, the parse location, and line and column |
|
positions within the parsed string. |
|
""" |
|
return strg.count("\n",0,loc) + 1 |
|
|
|
def line( loc, strg ): |
|
"""Returns the line of text containing loc within a string, counting newlines as line separators. |
|
""" |
|
lastCR = strg.rfind("\n", 0, loc) |
|
nextCR = strg.find("\n", loc) |
|
if nextCR >= 0: |
|
return strg[lastCR+1:nextCR] |
|
else: |
|
return strg[lastCR+1:] |
|
|
|
def _defaultStartDebugAction( instring, loc, expr ): |
|
print (("Match " + _ustr(expr) + " at loc " + _ustr(loc) + "(%d,%d)" % ( lineno(loc,instring), col(loc,instring) ))) |
|
|
|
def _defaultSuccessDebugAction( instring, startloc, endloc, expr, toks ): |
|
print ("Matched " + _ustr(expr) + " -> " + str(toks.asList())) |
|
|
|
def _defaultExceptionDebugAction( instring, loc, expr, exc ): |
|
print ("Exception raised:" + _ustr(exc)) |
|
|
|
def nullDebugAction(*args): |
|
"""'Do-nothing' debug action, to suppress debugging output during parsing.""" |
|
pass |
|
|
|
# Only works on Python 3.x - nonlocal is toxic to Python 2 installs |
|
#~ 'decorator to trim function calls to match the arity of the target' |
|
#~ def _trim_arity(func, maxargs=3): |
|
#~ if func in singleArgBuiltins: |
|
#~ return lambda s,l,t: func(t) |
|
#~ limit = 0 |
|
#~ foundArity = False |
|
#~ def wrapper(*args): |
|
#~ nonlocal limit,foundArity |
|
#~ while 1: |
|
#~ try: |
|
#~ ret = func(*args[limit:]) |
|
#~ foundArity = True |
|
#~ return ret |
|
#~ except TypeError: |
|
#~ if limit == maxargs or foundArity: |
|
#~ raise |
|
#~ limit += 1 |
|
#~ continue |
|
#~ return wrapper |
|
|
|
# this version is Python 2.x-3.x cross-compatible |
|
'decorator to trim function calls to match the arity of the target' |
|
def _trim_arity(func, maxargs=2): |
|
if func in singleArgBuiltins: |
|
return lambda s,l,t: func(t) |
|
limit = [0] |
|
foundArity = [False] |
|
|
|
# traceback return data structure changed in Py3.5 - normalize back to plain tuples |
|
if system_version[:2] >= (3,5): |
|
def extract_stack(limit=0): |
|
# special handling for Python 3.5.0 - extra deep call stack by 1 |
|
offset = -3 if system_version == (3,5,0) else -2 |
|
frame_summary = traceback.extract_stack(limit=-offset+limit-1)[offset] |
|
return [frame_summary[:2]] |
|
def extract_tb(tb, limit=0): |
|
frames = traceback.extract_tb(tb, limit=limit) |
|
frame_summary = frames[-1] |
|
return [frame_summary[:2]] |
|
else: |
|
extract_stack = traceback.extract_stack |
|
extract_tb = traceback.extract_tb |
|
|
|
# synthesize what would be returned by traceback.extract_stack at the call to |
|
# user's parse action 'func', so that we don't incur call penalty at parse time |
|
|
|
LINE_DIFF = 6 |
|
# IF ANY CODE CHANGES, EVEN JUST COMMENTS OR BLANK LINES, BETWEEN THE NEXT LINE AND |
|
# THE CALL TO FUNC INSIDE WRAPPER, LINE_DIFF MUST BE MODIFIED!!!! |
|
this_line = extract_stack(limit=2)[-1] |
|
pa_call_line_synth = (this_line[0], this_line[1]+LINE_DIFF) |
|
|
|
def wrapper(*args): |
|
while 1: |
|
try: |
|
ret = func(*args[limit[0]:]) |
|
foundArity[0] = True |
|
return ret |
|
except TypeError: |
|
# re-raise TypeErrors if they did not come from our arity testing |
|
if foundArity[0]: |
|
raise |
|
else: |
|
try: |
|
tb = sys.exc_info()[-1] |
|
if not extract_tb(tb, limit=2)[-1][:2] == pa_call_line_synth: |
|
raise |
|
finally: |
|
del tb |
|
|
|
if limit[0] <= maxargs: |
|
limit[0] += 1 |
|
continue |
|
raise |
|
|
|
# copy func name to wrapper for sensible debug output |
|
func_name = "<parse action>" |
|
try: |
|
func_name = getattr(func, '__name__', |
|
getattr(func, '__class__').__name__) |
|
except Exception: |
|
func_name = str(func) |
|
wrapper.__name__ = func_name |
|
|
|
return wrapper |
|
|
|
class ParserElement(object): |
|
"""Abstract base level parser element class.""" |
|
DEFAULT_WHITE_CHARS = " \n\t\r" |
|
verbose_stacktrace = False |
|
|
|
@staticmethod |
|
def setDefaultWhitespaceChars( chars ): |
|
r""" |
|
Overrides the default whitespace chars |
|
|
|
Example:: |
|
# default whitespace chars are space, <TAB> and newline |
|
OneOrMore(Word(alphas)).parseString("abc def\nghi jkl") # -> ['abc', 'def', 'ghi', 'jkl'] |
|
|
|
# change to just treat newline as significant |
|
ParserElement.setDefaultWhitespaceChars(" \t") |
|
OneOrMore(Word(alphas)).parseString("abc def\nghi jkl") # -> ['abc', 'def'] |
|
""" |
|
ParserElement.DEFAULT_WHITE_CHARS = chars |
|
|
|
@staticmethod |
|
def inlineLiteralsUsing(cls): |
|
""" |
|
Set class to be used for inclusion of string literals into a parser. |
|
|
|
Example:: |
|
# default literal class used is Literal |
|
integer = Word(nums) |
|
date_str = integer("year") + '/' + integer("month") + '/' + integer("day") |
|
|
|
date_str.parseString("1999/12/31") # -> ['1999', '/', '12', '/', '31'] |
|
|
|
|
|
# change to Suppress |
|
ParserElement.inlineLiteralsUsing(Suppress) |
|
date_str = integer("year") + '/' + integer("month") + '/' + integer("day") |
|
|
|
date_str.parseString("1999/12/31") # -> ['1999', '12', '31'] |
|
""" |
|
ParserElement._literalStringClass = cls |
|
|
|
def __init__( self, savelist=False ): |
|
self.parseAction = list() |
|
self.failAction = None |
|
#~ self.name = "<unknown>" # don't define self.name, let subclasses try/except upcall |
|
self.strRepr = None |
|
self.resultsName = None |
|
self.saveAsList = savelist |
|
self.skipWhitespace = True |
|
self.whiteChars = ParserElement.DEFAULT_WHITE_CHARS |
|
self.copyDefaultWhiteChars = True |
|
self.mayReturnEmpty = False # used when checking for left-recursion |
|
self.keepTabs = False |
|
self.ignoreExprs = list() |
|
self.debug = False |
|
self.streamlined = False |
|
self.mayIndexError = True # used to optimize exception handling for subclasses that don't advance parse index |
|
self.errmsg = "" |
|
self.modalResults = True # used to mark results names as modal (report only last) or cumulative (list all) |
|
self.debugActions = ( None, None, None ) #custom debug actions |
|
self.re = None |
|
self.callPreparse = True # used to avoid redundant calls to preParse |
|
self.callDuringTry = False |
|
|
|
def copy( self ): |
|
""" |
|
Make a copy of this C{ParserElement}. Useful for defining different parse actions |
|
for the same parsing pattern, using copies of the original parse element. |
|
|
|
Example:: |
|
integer = Word(nums).setParseAction(lambda toks: int(toks[0])) |
|
integerK = integer.copy().addParseAction(lambda toks: toks[0]*1024) + Suppress("K") |
|
integerM = integer.copy().addParseAction(lambda toks: toks[0]*1024*1024) + Suppress("M") |
|
|
|
print(OneOrMore(integerK | integerM | integer).parseString("5K 100 640K 256M")) |
|
prints:: |
|
[5120, 100, 655360, 268435456] |
|
Equivalent form of C{expr.copy()} is just C{expr()}:: |
|
integerM = integer().addParseAction(lambda toks: toks[0]*1024*1024) + Suppress("M") |
|
""" |
|
cpy = copy.copy( self ) |
|
cpy.parseAction = self.parseAction[:] |
|
cpy.ignoreExprs = self.ignoreExprs[:] |
|
if self.copyDefaultWhiteChars: |
|
cpy.whiteChars = ParserElement.DEFAULT_WHITE_CHARS |
|
return cpy |
|
|
|
def setName( self, name ): |
|
""" |
|
Define name for this expression, makes debugging and exception messages clearer. |
|
|
|
Example:: |
|
Word(nums).parseString("ABC") # -> Exception: Expected W:(0123...) (at char 0), (line:1, col:1) |
|
Word(nums).setName("integer").parseString("ABC") # -> Exception: Expected integer (at char 0), (line:1, col:1) |
|
""" |
|
self.name = name |
|
self.errmsg = "Expected " + self.name |
|
if hasattr(self,"exception"): |
|
self.exception.msg = self.errmsg |
|
return self |
|
|
|
def setResultsName( self, name, listAllMatches=False ): |
|
""" |
|
Define name for referencing matching tokens as a nested attribute |
|
of the returned parse results. |
|
NOTE: this returns a *copy* of the original C{ParserElement} object; |
|
this is so that the client can define a basic element, such as an |
|
integer, and reference it in multiple places with different names. |
|
|
|
You can also set results names using the abbreviated syntax, |
|
C{expr("name")} in place of C{expr.setResultsName("name")} - |
|
see L{I{__call__}<__call__>}. |
|
|
|
Example:: |
|
date_str = (integer.setResultsName("year") + '/' |
|
+ integer.setResultsName("month") + '/' |
|
+ integer.setResultsName("day")) |
|
|
|
# equivalent form: |
|
date_str = integer("year") + '/' + integer("month") + '/' + integer("day") |
|
""" |
|
newself = self.copy() |
|
if name.endswith("*"): |
|
name = name[:-1] |
|
listAllMatches=True |
|
newself.resultsName = name |
|
newself.modalResults = not listAllMatches |
|
return newself |
|
|
|
def setBreak(self,breakFlag = True): |
|
"""Method to invoke the Python pdb debugger when this element is |
|
about to be parsed. Set C{breakFlag} to True to enable, False to |
|
disable. |
|
""" |
|
if breakFlag: |
|
_parseMethod = self._parse |
|
def breaker(instring, loc, doActions=True, callPreParse=True): |
|
import pdb |
|
pdb.set_trace() |
|
return _parseMethod( instring, loc, doActions, callPreParse ) |
|
breaker._originalParseMethod = _parseMethod |
|
self._parse = breaker |
|
else: |
|
if hasattr(self._parse,"_originalParseMethod"): |
|
self._parse = self._parse._originalParseMethod |
|
return self |
|
|
|
def setParseAction( self, *fns, **kwargs ): |
|
""" |
|
Define one or more actions to perform when successfully matching parse element definition. |
|
Parse action fn is a callable method with 0-3 arguments, called as C{fn(s,loc,toks)}, |
|
C{fn(loc,toks)}, C{fn(toks)}, or just C{fn()}, where: |
|
- s = the original string being parsed (see note below) |
|
- loc = the location of the matching substring |
|
- toks = a list of the matched tokens, packaged as a C{L{ParseResults}} object |
|
If the functions in fns modify the tokens, they can return them as the return |
|
value from fn, and the modified list of tokens will replace the original. |
|
Otherwise, fn does not need to return any value. |
|
|
|
Optional keyword arguments: |
|
- callDuringTry = (default=C{False}) indicate if parse action should be run during lookaheads and alternate testing |
|
|
|
Note: the default parsing behavior is to expand tabs in the input string |
|
before starting the parsing process. See L{I{parseString}<parseString>} for more information |
|
on parsing strings containing C{<TAB>}s, and suggested methods to maintain a |
|
consistent view of the parsed string, the parse location, and line and column |
|
positions within the parsed string. |
|
|
|
Example:: |
|
integer = Word(nums) |
|
date_str = integer + '/' + integer + '/' + integer |
|
|
|
date_str.parseString("1999/12/31") # -> ['1999', '/', '12', '/', '31'] |
|
|
|
# use parse action to convert to ints at parse time |
|
integer = Word(nums).setParseAction(lambda toks: int(toks[0])) |
|
date_str = integer + '/' + integer + '/' + integer |
|
|
|
# note that integer fields are now ints, not strings |
|
date_str.parseString("1999/12/31") # -> [1999, '/', 12, '/', 31] |
|
""" |
|
self.parseAction = list(map(_trim_arity, list(fns))) |
|
self.callDuringTry = kwargs.get("callDuringTry", False) |
|
return self |
|
|
|
def addParseAction( self, *fns, **kwargs ): |
|
""" |
|
Add one or more parse actions to expression's list of parse actions. See L{I{setParseAction}<setParseAction>}. |
|
|
|
See examples in L{I{copy}<copy>}. |
|
""" |
|
self.parseAction += list(map(_trim_arity, list(fns))) |
|
self.callDuringTry = self.callDuringTry or kwargs.get("callDuringTry", False) |
|
return self |
|
|
|
def addCondition(self, *fns, **kwargs): |
|
"""Add a boolean predicate function to expression's list of parse actions. See |
|
L{I{setParseAction}<setParseAction>} for function call signatures. Unlike C{setParseAction}, |
|
functions passed to C{addCondition} need to return boolean success/fail of the condition. |
|
|
|
Optional keyword arguments: |
|
- message = define a custom message to be used in the raised exception |
|
- fatal = if True, will raise ParseFatalException to stop parsing immediately; otherwise will raise ParseException |
|
|
|
Example:: |
|
integer = Word(nums).setParseAction(lambda toks: int(toks[0])) |
|
year_int = integer.copy() |
|
year_int.addCondition(lambda toks: toks[0] >= 2000, message="Only support years 2000 and later") |
|
date_str = year_int + '/' + integer + '/' + integer |
|
|
|
result = date_str.parseString("1999/12/31") # -> Exception: Only support years 2000 and later (at char 0), (line:1, col:1) |
|
""" |
|
msg = kwargs.get("message", "failed user-defined condition") |
|
exc_type = ParseFatalException if kwargs.get("fatal", False) else ParseException |
|
for fn in fns: |
|
def pa(s,l,t): |
|
if not bool(_trim_arity(fn)(s,l,t)): |
|
raise exc_type(s,l,msg) |
|
self.parseAction.append(pa) |
|
self.callDuringTry = self.callDuringTry or kwargs.get("callDuringTry", False) |
|
return self |
|
|
|
def setFailAction( self, fn ): |
|
"""Define action to perform if parsing fails at this expression. |
|
Fail acton fn is a callable function that takes the arguments |
|
C{fn(s,loc,expr,err)} where: |
|
- s = string being parsed |
|
- loc = location where expression match was attempted and failed |
|
- expr = the parse expression that failed |
|
- err = the exception thrown |
|
The function returns no value. It may throw C{L{ParseFatalException}} |
|
if it is desired to stop parsing immediately.""" |
|
self.failAction = fn |
|
return self |
|
|
|
def _skipIgnorables( self, instring, loc ): |
|
exprsFound = True |
|
while exprsFound: |
|
exprsFound = False |
|
for e in self.ignoreExprs: |
|
try: |
|
while 1: |
|
loc,dummy = e._parse( instring, loc ) |
|
exprsFound = True |
|
except ParseException: |
|
pass |
|
return loc |
|
|
|
def preParse( self, instring, loc ): |
|
if self.ignoreExprs: |
|
loc = self._skipIgnorables( instring, loc ) |
|
|
|
if self.skipWhitespace: |
|
wt = self.whiteChars |
|
instrlen = len(instring) |
|
while loc < instrlen and instring[loc] in wt: |
|
loc += 1 |
|
|
|
return loc |
|
|
|
def parseImpl( self, instring, loc, doActions=True ): |
|
return loc, [] |
|
|
|
def postParse( self, instring, loc, tokenlist ): |
|
return tokenlist |
|
|
|
#~ @profile |
|
def _parseNoCache( self, instring, loc, doActions=True, callPreParse=True ): |
|
debugging = ( self.debug ) #and doActions ) |
|
|
|
if debugging or self.failAction: |
|
#~ print ("Match",self,"at loc",loc,"(%d,%d)" % ( lineno(loc,instring), col(loc,instring) )) |
|
if (self.debugActions[0] ): |
|
self.debugActions[0]( instring, loc, self ) |
|
if callPreParse and self.callPreparse: |
|
preloc = self.preParse( instring, loc ) |
|
else: |
|
preloc = loc |
|
tokensStart = preloc |
|
try: |
|
try: |
|
loc,tokens = self.parseImpl( instring, preloc, doActions ) |
|
except IndexError: |
|
raise ParseException( instring, len(instring), self.errmsg, self ) |
|
except ParseBaseException as err: |
|
#~ print ("Exception raised:", err) |
|
if self.debugActions[2]: |
|
self.debugActions[2]( instring, tokensStart, self, err ) |
|
if self.failAction: |
|
self.failAction( instring, tokensStart, self, err ) |
|
raise |
|
else: |
|
if callPreParse and self.callPreparse: |
|
preloc = self.preParse( instring, loc ) |
|
else: |
|
preloc = loc |
|
tokensStart = preloc |
|
if self.mayIndexError or preloc >= len(instring): |
|
try: |
|
loc,tokens = self.parseImpl( instring, preloc, doActions ) |
|
except IndexError: |
|
raise ParseException( instring, len(instring), self.errmsg, self ) |
|
else: |
|
loc,tokens = self.parseImpl( instring, preloc, doActions ) |
|
|
|
tokens = self.postParse( instring, loc, tokens ) |
|
|
|
retTokens = ParseResults( tokens, self.resultsName, asList=self.saveAsList, modal=self.modalResults ) |
|
if self.parseAction and (doActions or self.callDuringTry): |
|
if debugging: |
|
try: |
|
for fn in self.parseAction: |
|
tokens = fn( instring, tokensStart, retTokens ) |
|
if tokens is not None: |
|
retTokens = ParseResults( tokens, |
|
self.resultsName, |
|
asList=self.saveAsList and isinstance(tokens,(ParseResults,list)), |
|
modal=self.modalResults ) |
|
except ParseBaseException as err: |
|
#~ print "Exception raised in user parse action:", err |
|
if (self.debugActions[2] ): |
|
self.debugActions[2]( instring, tokensStart, self, err ) |
|
raise |
|
else: |
|
for fn in self.parseAction: |
|
tokens = fn( instring, tokensStart, retTokens ) |
|
if tokens is not None: |
|
retTokens = ParseResults( tokens, |
|
self.resultsName, |
|
asList=self.saveAsList and isinstance(tokens,(ParseResults,list)), |
|
modal=self.modalResults ) |
|
if debugging: |
|
#~ print ("Matched",self,"->",retTokens.asList()) |
|
if (self.debugActions[1] ): |
|
self.debugActions[1]( instring, tokensStart, loc, self, retTokens ) |
|
|
|
return loc, retTokens |
|
|
|
def tryParse( self, instring, loc ): |
|
try: |
|
return self._parse( instring, loc, doActions=False )[0] |
|
except ParseFatalException: |
|
raise ParseException( instring, loc, self.errmsg, self) |
|
|
|
def canParseNext(self, instring, loc): |
|
try: |
|
self.tryParse(instring, loc) |
|
except (ParseException, IndexError): |
|
return False |
|
else: |
|
return True |
|
|
|
class _UnboundedCache(object): |
|
def __init__(self): |
|
cache = {} |
|
self.not_in_cache = not_in_cache = object() |
|
|
|
def get(self, key): |
|
return cache.get(key, not_in_cache) |
|
|
|
def set(self, key, value): |
|
cache[key] = value |
|
|
|
def clear(self): |
|
cache.clear() |
|
|
|
def cache_len(self): |
|
return len(cache) |
|
|
|
self.get = types.MethodType(get, self) |
|
self.set = types.MethodType(set, self) |
|
self.clear = types.MethodType(clear, self) |
|
self.__len__ = types.MethodType(cache_len, self) |
|
|
|
if _OrderedDict is not None: |
|
class _FifoCache(object): |
|
def __init__(self, size): |
|
self.not_in_cache = not_in_cache = object() |
|
|
|
cache = _OrderedDict() |
|
|
|
def get(self, key): |
|
return cache.get(key, not_in_cache) |
|
|
|
def set(self, key, value): |
|
cache[key] = value |
|
while len(cache) > size: |
|
try: |
|
cache.popitem(False) |
|
except KeyError: |
|
pass |
|
|
|
def clear(self): |
|
cache.clear() |
|
|
|
def cache_len(self): |
|
return len(cache) |
|
|
|
self.get = types.MethodType(get, self) |
|
self.set = types.MethodType(set, self) |
|
self.clear = types.MethodType(clear, self) |
|
self.__len__ = types.MethodType(cache_len, self) |
|
|
|
else: |
|
class _FifoCache(object): |
|
def __init__(self, size): |
|
self.not_in_cache = not_in_cache = object() |
|
|
|
cache = {} |
|
key_fifo = collections.deque([], size) |
|
|
|
def get(self, key): |
|
return cache.get(key, not_in_cache) |
|
|
|
def set(self, key, value): |
|
cache[key] = value |
|
while len(key_fifo) > size: |
|
cache.pop(key_fifo.popleft(), None) |
|
key_fifo.append(key) |
|
|
|
def clear(self): |
|
cache.clear() |
|
key_fifo.clear() |
|
|
|
def cache_len(self): |
|
return len(cache) |
|
|
|
self.get = types.MethodType(get, self) |
|
self.set = types.MethodType(set, self) |
|
self.clear = types.MethodType(clear, self) |
|
self.__len__ = types.MethodType(cache_len, self) |
|
|
|
# argument cache for optimizing repeated calls when backtracking through recursive expressions |
|
packrat_cache = {} # this is set later by enabledPackrat(); this is here so that resetCache() doesn't fail |
|
packrat_cache_lock = RLock() |
|
packrat_cache_stats = [0, 0] |
|
|
|
# this method gets repeatedly called during backtracking with the same arguments - |
|
# we can cache these arguments and save ourselves the trouble of re-parsing the contained expression |
|
def _parseCache( self, instring, loc, doActions=True, callPreParse=True ): |
|
HIT, MISS = 0, 1 |
|
lookup = (self, instring, loc, callPreParse, doActions) |
|
with ParserElement.packrat_cache_lock: |
|
cache = ParserElement.packrat_cache |
|
value = cache.get(lookup) |
|
if value is cache.not_in_cache: |
|
ParserElement.packrat_cache_stats[MISS] += 1 |
|
try: |
|
value = self._parseNoCache(instring, loc, doActions, callPreParse) |
|
except ParseBaseException as pe: |
|
# cache a copy of the exception, without the traceback |
|
cache.set(lookup, pe.__class__(*pe.args)) |
|
raise |
|
else: |
|
cache.set(lookup, (value[0], value[1].copy())) |
|
return value |
|
else: |
|
ParserElement.packrat_cache_stats[HIT] += 1 |
|
if isinstance(value, Exception): |
|
raise value |
|
return (value[0], value[1].copy()) |
|
|
|
_parse = _parseNoCache |
|
|
|
@staticmethod |
|
def resetCache(): |
|
ParserElement.packrat_cache.clear() |
|
ParserElement.packrat_cache_stats[:] = [0] * len(ParserElement.packrat_cache_stats) |
|
|
|
_packratEnabled = False |
|
@staticmethod |
|
def enablePackrat(cache_size_limit=128): |
|
"""Enables "packrat" parsing, which adds memoizing to the parsing logic. |
|
Repeated parse attempts at the same string location (which happens |
|
often in many complex grammars) can immediately return a cached value, |
|
instead of re-executing parsing/validating code. Memoizing is done of |
|
both valid results and parsing exceptions. |
|
|
|
Parameters: |
|
- cache_size_limit - (default=C{128}) - if an integer value is provided |
|
will limit the size of the packrat cache; if None is passed, then |
|
the cache size will be unbounded; if 0 is passed, the cache will |
|
be effectively disabled. |
|
|
|
This speedup may break existing programs that use parse actions that |
|
have side-effects. For this reason, packrat parsing is disabled when |
|
you first import pyparsing. To activate the packrat feature, your |
|
program must call the class method C{ParserElement.enablePackrat()}. If |
|
your program uses C{psyco} to "compile as you go", you must call |
|
C{enablePackrat} before calling C{psyco.full()}. If you do not do this, |
|
Python will crash. For best results, call C{enablePackrat()} immediately |
|
after importing pyparsing. |
|
|
|
Example:: |
|
import pyparsing |
|
pyparsing.ParserElement.enablePackrat() |
|
""" |
|
if not ParserElement._packratEnabled: |
|
ParserElement._packratEnabled = True |
|
if cache_size_limit is None: |
|
ParserElement.packrat_cache = ParserElement._UnboundedCache() |
|
else: |
|
ParserElement.packrat_cache = ParserElement._FifoCache(cache_size_limit) |
|
ParserElement._parse = ParserElement._parseCache |
|
|
|
def parseString( self, instring, parseAll=False ): |
|
""" |
|
Execute the parse expression with the given string. |
|
This is the main interface to the client code, once the complete |
|
expression has been built. |
|
|
|
If you want the grammar to require that the entire input string be |
|
successfully parsed, then set C{parseAll} to True (equivalent to ending |
|
the grammar with C{L{StringEnd()}}). |
|
|
|
Note: C{parseString} implicitly calls C{expandtabs()} on the input string, |
|
in order to report proper column numbers in parse actions. |
|
If the input string contains tabs and |
|
the grammar uses parse actions that use the C{loc} argument to index into the |
|
string being parsed, you can ensure you have a consistent view of the input |
|
string by: |
|
- calling C{parseWithTabs} on your grammar before calling C{parseString} |
|
(see L{I{parseWithTabs}<parseWithTabs>}) |
|
- define your parse action using the full C{(s,loc,toks)} signature, and |
|
reference the input string using the parse action's C{s} argument |
|
- explicitly expand the tabs in your input string before calling |
|
C{parseString} |
|
|
|
Example:: |
|
Word('a').parseString('aaaaabaaa') # -> ['aaaaa'] |
|
Word('a').parseString('aaaaabaaa', parseAll=True) # -> Exception: Expected end of text |
|
""" |
|
ParserElement.resetCache() |
|
if not self.streamlined: |
|
self.streamline() |
|
#~ self.saveAsList = True |
|
for e in self.ignoreExprs: |
|
e.streamline() |
|
if not self.keepTabs: |
|
instring = instring.expandtabs() |
|
try: |
|
loc, tokens = self._parse( instring, 0 ) |
|
if parseAll: |
|
loc = self.preParse( instring, loc ) |
|
se = Empty() + StringEnd() |
|
se._parse( instring, loc ) |
|
except ParseBaseException as exc: |
|
if ParserElement.verbose_stacktrace: |
|
raise |
|
else: |
|
# catch and re-raise exception from here, clears out pyparsing internal stack trace |
|
raise exc |
|
else: |
|
return tokens |
|
|
|
def scanString( self, instring, maxMatches=_MAX_INT, overlap=False ): |
|
""" |
|
Scan the input string for expression matches. Each match will return the |
|
matching tokens, start location, and end location. May be called with optional |
|
C{maxMatches} argument, to clip scanning after 'n' matches are found. If |
|
C{overlap} is specified, then overlapping matches will be reported. |
|
|
|
Note that the start and end locations are reported relative to the string |
|
being parsed. See L{I{parseString}<parseString>} for more information on parsing |
|
strings with embedded tabs. |
|
|
|
Example:: |
|
source = "sldjf123lsdjjkf345sldkjf879lkjsfd987" |
|
print(source) |
|
for tokens,start,end in Word(alphas).scanString(source): |
|
print(' '*start + '^'*(end-start)) |
|
print(' '*start + tokens[0]) |
|
|
|
prints:: |
|
|
|
sldjf123lsdjjkf345sldkjf879lkjsfd987 |
|
^^^^^ |
|
sldjf |
|
^^^^^^^ |
|
lsdjjkf |
|
^^^^^^ |
|
sldkjf |
|
^^^^^^ |
|
lkjsfd |
|
""" |
|
if not self.streamlined: |
|
self.streamline() |
|
for e in self.ignoreExprs: |
|
e.streamline() |
|
|
|
if not self.keepTabs: |
|
instring = _ustr(instring).expandtabs() |
|
instrlen = len(instring) |
|
loc = 0 |
|
preparseFn = self.preParse |
|
parseFn = self._parse |
|
ParserElement.resetCache() |
|
matches = 0 |
|
try: |
|
while loc <= instrlen and matches < maxMatches: |
|
try: |
|
preloc = preparseFn( instring, loc ) |
|
nextLoc,tokens = parseFn( instring, preloc, callPreParse=False ) |
|
except ParseException: |
|
loc = preloc+1 |
|
else: |
|
if nextLoc > loc: |
|
matches += 1 |
|
yield tokens, preloc, nextLoc |
|
if overlap: |
|
nextloc = preparseFn( instring, loc ) |
|
if nextloc > loc: |
|
loc = nextLoc |
|
else: |
|
loc += 1 |
|
else: |
|
loc = nextLoc |
|
else: |
|
loc = preloc+1 |
|
except ParseBaseException as exc: |
|
if ParserElement.verbose_stacktrace: |
|
raise |
|
else: |
|
# catch and re-raise exception from here, clears out pyparsing internal stack trace |
|
raise exc |
|
|
|
def transformString( self, instring ): |
|
""" |
|
Extension to C{L{scanString}}, to modify matching text with modified tokens that may |
|
be returned from a parse action. To use C{transformString}, define a grammar and |
|
attach a parse action to it that modifies the returned token list. |
|
Invoking C{transformString()} on a target string will then scan for matches, |
|
and replace the matched text patterns according to the logic in the parse |
|
action. C{transformString()} returns the resulting transformed string. |
|
|
|
Example:: |
|
wd = Word(alphas) |
|
wd.setParseAction(lambda toks: toks[0].title()) |
|
|
|
print(wd.transformString("now is the winter of our discontent made glorious summer by this sun of york.")) |
|
Prints:: |
|
Now Is The Winter Of Our Discontent Made Glorious Summer By This Sun Of York. |
|
""" |
|
out = [] |
|
lastE = 0 |
|
# force preservation of <TAB>s, to minimize unwanted transformation of string, and to |
|
# keep string locs straight between transformString and scanString |
|
self.keepTabs = True |
|
try: |
|
for t,s,e in self.scanString( instring ): |
|
out.append( instring[lastE:s] ) |
|
if t: |
|
if isinstance(t,ParseResults): |
|
out += t.asList() |
|
elif isinstance(t,list): |
|
out += t |
|
else: |
|
out.append(t) |
|
lastE = e |
|
out.append(instring[lastE:]) |
|
out = [o for o in out if o] |
|
return "".join(map(_ustr,_flatten(out))) |
|
except ParseBaseException as exc: |
|
if ParserElement.verbose_stacktrace: |
|
raise |
|
else: |
|
# catch and re-raise exception from here, clears out pyparsing internal stack trace |
|
raise exc |
|
|
|
def searchString( self, instring, maxMatches=_MAX_INT ): |
|
""" |
|
Another extension to C{L{scanString}}, simplifying the access to the tokens found |
|
to match the given parse expression. May be called with optional |
|
C{maxMatches} argument, to clip searching after 'n' matches are found. |
|
|
|
Example:: |
|
# a capitalized word starts with an uppercase letter, followed by zero or more lowercase letters |
|
cap_word = Word(alphas.upper(), alphas.lower()) |
|
|
|
print(cap_word.searchString("More than Iron, more than Lead, more than Gold I need Electricity")) |
|
|
|
# the sum() builtin can be used to merge results into a single ParseResults object |
|
print(sum(cap_word.searchString("More than Iron, more than Lead, more than Gold I need Electricity"))) |
|
prints:: |
|
[['More'], ['Iron'], ['Lead'], ['Gold'], ['I'], ['Electricity']] |
|
['More', 'Iron', 'Lead', 'Gold', 'I', 'Electricity'] |
|
""" |
|
try: |
|
return ParseResults([ t for t,s,e in self.scanString( instring, maxMatches ) ]) |
|
except ParseBaseException as exc: |
|
if ParserElement.verbose_stacktrace: |
|
raise |
|
else: |
|
# catch and re-raise exception from here, clears out pyparsing internal stack trace |
|
raise exc |
|
|
|
def split(self, instring, maxsplit=_MAX_INT, includeSeparators=False): |
|
""" |
|
Generator method to split a string using the given expression as a separator. |
|
May be called with optional C{maxsplit} argument, to limit the number of splits; |
|
and the optional C{includeSeparators} argument (default=C{False}), if the separating |
|
matching text should be included in the split results. |
|
|
|
Example:: |
|
punc = oneOf(list(".,;:/-!?")) |
|
print(list(punc.split("This, this?, this sentence, is badly punctuated!"))) |
|
prints:: |
|
['This', ' this', '', ' this sentence', ' is badly punctuated', ''] |
|
""" |
|
splits = 0 |
|
last = 0 |
|
for t,s,e in self.scanString(instring, maxMatches=maxsplit): |
|
yield instring[last:s] |
|
if includeSeparators: |
|
yield t[0] |
|
last = e |
|
yield instring[last:] |
|
|
|
def __add__(self, other ): |
|
""" |
|
Implementation of + operator - returns C{L{And}}. Adding strings to a ParserElement |
|
converts them to L{Literal}s by default. |
|
|
|
Example:: |
|
greet = Word(alphas) + "," + Word(alphas) + "!" |
|
hello = "Hello, World!" |
|
print (hello, "->", greet.parseString(hello)) |
|
Prints:: |
|
Hello, World! -> ['Hello', ',', 'World', '!'] |
|
""" |
|
if isinstance( other, basestring ): |
|
other = ParserElement._literalStringClass( other ) |
|
if not isinstance( other, ParserElement ): |
|
warnings.warn("Cannot combine element of type %s with ParserElement" % type(other), |
|
SyntaxWarning, stacklevel=2) |
|
return None |
|
return And( [ self, other ] ) |
|
|
|
def __radd__(self, other ): |
|
""" |
|
Implementation of + operator when left operand is not a C{L{ParserElement}} |
|
""" |
|
if isinstance( other, basestring ): |
|
other = ParserElement._literalStringClass( other ) |
|
if not isinstance( other, ParserElement ): |
|
warnings.warn("Cannot combine element of type %s with ParserElement" % type(other), |
|
SyntaxWarning, stacklevel=2) |
|
return None |
|
return other + self |
|
|
|
def __sub__(self, other): |
|
""" |
|
Implementation of - operator, returns C{L{And}} with error stop |
|
""" |
|
if isinstance( other, basestring ): |
|
other = ParserElement._literalStringClass( other ) |
|
if not isinstance( other, ParserElement ): |
|
warnings.warn("Cannot combine element of type %s with ParserElement" % type(other), |
|
SyntaxWarning, stacklevel=2) |
|
return None |
|
return self + And._ErrorStop() + other |
|
|
|
def __rsub__(self, other ): |
|
""" |
|
Implementation of - operator when left operand is not a C{L{ParserElement}} |
|
""" |
|
if isinstance( other, basestring ): |
|
other = ParserElement._literalStringClass( other ) |
|
if not isinstance( other, ParserElement ): |
|
warnings.warn("Cannot combine element of type %s with ParserElement" % type(other), |
|
SyntaxWarning, stacklevel=2) |
|
return None |
|
return other - self |
|
|
|
def __mul__(self,other): |
|
""" |
|
Implementation of * operator, allows use of C{expr * 3} in place of |
|
C{expr + expr + expr}. Expressions may also me multiplied by a 2-integer |
|
tuple, similar to C{{min,max}} multipliers in regular expressions. Tuples |
|
may also include C{None} as in: |
|
- C{expr*(n,None)} or C{expr*(n,)} is equivalent |
|
to C{expr*n + L{ZeroOrMore}(expr)} |
|
(read as "at least n instances of C{expr}") |
|
- C{expr*(None,n)} is equivalent to C{expr*(0,n)} |
|
(read as "0 to n instances of C{expr}") |
|
- C{expr*(None,None)} is equivalent to C{L{ZeroOrMore}(expr)} |
|
- C{expr*(1,None)} is equivalent to C{L{OneOrMore}(expr)} |
|
|
|
Note that C{expr*(None,n)} does not raise an exception if |
|
more than n exprs exist in the input stream; that is, |
|
C{expr*(None,n)} does not enforce a maximum number of expr |
|
occurrences. If this behavior is desired, then write |
|
C{expr*(None,n) + ~expr} |
|
""" |
|
if isinstance(other,int): |
|
minElements, optElements = other,0 |
|
elif isinstance(other,tuple): |
|
other = (other + (None, None))[:2] |
|
if other[0] is None: |
|
other = (0, other[1]) |
|
if isinstance(other[0],int) and other[1] is None: |
|
if other[0] == 0: |
|
return ZeroOrMore(self) |
|
if other[0] == 1: |
|
return OneOrMore(self) |
|
else: |
|
return self*other[0] + ZeroOrMore(self) |
|
elif isinstance(other[0],int) and isinstance(other[1],int): |
|
minElements, optElements = other |
|
optElements -= minElements |
|
else: |
|
raise TypeError("cannot multiply 'ParserElement' and ('%s','%s') objects", type(other[0]),type(other[1])) |
|
else: |
|
raise TypeError("cannot multiply 'ParserElement' and '%s' objects", type(other)) |
|
|
|
if minElements < 0: |
|
raise ValueError("cannot multiply ParserElement by negative value") |
|
if optElements < 0: |
|
raise ValueError("second tuple value must be greater or equal to first tuple value") |
|
if minElements == optElements == 0: |
|
raise ValueError("cannot multiply ParserElement by 0 or (0,0)") |
|
|
|
if (optElements): |
|
def makeOptionalList(n): |
|
if n>1: |
|
return Optional(self + makeOptionalList(n-1)) |
|
else: |
|
return Optional(self) |
|
if minElements: |
|
if minElements == 1: |
|
ret = self + makeOptionalList(optElements) |
|
else: |
|
ret = And([self]*minElements) + makeOptionalList(optElements) |
|
else: |
|
ret = makeOptionalList(optElements) |
|
else: |
|
if minElements == 1: |
|
ret = self |
|
else: |
|
ret = And([self]*minElements) |
|
return ret |
|
|
|
def __rmul__(self, other): |
|
return self.__mul__(other) |
|
|
|
def __or__(self, other ): |
|
""" |
|
Implementation of | operator - returns C{L{MatchFirst}} |
|
""" |
|
if isinstance( other, basestring ): |
|
other = ParserElement._literalStringClass( other ) |
|
if not isinstance( other, ParserElement ): |
|
warnings.warn("Cannot combine element of type %s with ParserElement" % type(other), |
|
SyntaxWarning, stacklevel=2) |
|
return None |
|
return MatchFirst( [ self, other ] ) |
|
|
|
def __ror__(self, other ): |
|
""" |
|
Implementation of | operator when left operand is not a C{L{ParserElement}} |
|
""" |
|
if isinstance( other, basestring ): |
|
other = ParserElement._literalStringClass( other ) |
|
if not isinstance( other, ParserElement ): |
|
warnings.warn("Cannot combine element of type %s with ParserElement" % type(other), |
|
SyntaxWarning, stacklevel=2) |
|
return None |
|
return other | self |
|
|
|
def __xor__(self, other ): |
|
""" |
|
Implementation of ^ operator - returns C{L{Or}} |
|
""" |
|
if isinstance( other, basestring ): |
|
other = ParserElement._literalStringClass( other ) |
|
if not isinstance( other, ParserElement ): |
|
warnings.warn("Cannot combine element of type %s with ParserElement" % type(other), |
|
SyntaxWarning, stacklevel=2) |
|
return None |
|
return Or( [ self, other ] ) |
|
|
|
def __rxor__(self, other ): |
|
""" |
|
Implementation of ^ operator when left operand is not a C{L{ParserElement}} |
|
""" |
|
if isinstance( other, basestring ): |
|
other = ParserElement._literalStringClass( other ) |
|
if not isinstance( other, ParserElement ): |
|
warnings.warn("Cannot combine element of type %s with ParserElement" % type(other), |
|
SyntaxWarning, stacklevel=2) |
|
return None |
|
return other ^ self |
|
|
|
def __and__(self, other ): |
|
""" |
|
Implementation of & operator - returns C{L{Each}} |
|
""" |
|
if isinstance( other, basestring ): |
|
other = ParserElement._literalStringClass( other ) |
|
if not isinstance( other, ParserElement ): |
|
warnings.warn("Cannot combine element of type %s with ParserElement" % type(other), |
|
SyntaxWarning, stacklevel=2) |
|
return None |
|
return Each( [ self, other ] ) |
|
|
|
def __rand__(self, other ): |
|
""" |
|
Implementation of & operator when left operand is not a C{L{ParserElement}} |
|
""" |
|
if isinstance( other, basestring ): |
|
other = ParserElement._literalStringClass( other ) |
|
if not isinstance( other, ParserElement ): |
|
warnings.warn("Cannot combine element of type %s with ParserElement" % type(other), |
|
SyntaxWarning, stacklevel=2) |
|
return None |
|
return other & self |
|
|
|
def __invert__( self ): |
|
""" |
|
Implementation of ~ operator - returns C{L{NotAny}} |
|
""" |
|
return NotAny( self ) |
|
|
|
def __call__(self, name=None): |
|
""" |
|
Shortcut for C{L{setResultsName}}, with C{listAllMatches=False}. |
|
|
|
If C{name} is given with a trailing C{'*'} character, then C{listAllMatches} will be |
|
passed as C{True}. |
|
|
|
If C{name} is omitted, same as calling C{L{copy}}. |
|
|
|
Example:: |
|
# these are equivalent |
|
userdata = Word(alphas).setResultsName("name") + Word(nums+"-").setResultsName("socsecno") |
|
userdata = Word(alphas)("name") + Word(nums+"-")("socsecno") |
|
""" |
|
if name is not None: |
|
return self.setResultsName(name) |
|
else: |
|
return self.copy() |
|
|
|
def suppress( self ): |
|
""" |
|
Suppresses the output of this C{ParserElement}; useful to keep punctuation from |
|
cluttering up returned output. |
|
""" |
|
return Suppress( self ) |
|
|
|
def leaveWhitespace( self ): |
|
""" |
|
Disables the skipping of whitespace before matching the characters in the |
|
C{ParserElement}'s defined pattern. This is normally only used internally by |
|
the pyparsing module, but may be needed in some whitespace-sensitive grammars. |
|
""" |
|
self.skipWhitespace = False |
|
return self |
|
|
|
def setWhitespaceChars( self, chars ): |
|
""" |
|
Overrides the default whitespace chars |
|
""" |
|
self.skipWhitespace = True |
|
self.whiteChars = chars |
|
self.copyDefaultWhiteChars = False |
|
return self |
|
|
|
def parseWithTabs( self ): |
|
""" |
|
Overrides default behavior to expand C{<TAB>}s to spaces before parsing the input string. |
|
Must be called before C{parseString} when the input grammar contains elements that |
|
match C{<TAB>} characters. |
|
""" |
|
self.keepTabs = True |
|
return self |
|
|
|
def ignore( self, other ): |
|
""" |
|
Define expression to be ignored (e.g., comments) while doing pattern |
|
matching; may be called repeatedly, to define multiple comment or other |
|
ignorable patterns. |
|
|
|
Example:: |
|
patt = OneOrMore(Word(alphas)) |
|
patt.parseString('ablaj /* comment */ lskjd') # -> ['ablaj'] |
|
|
|
patt.ignore(cStyleComment) |
|
patt.parseString('ablaj /* comment */ lskjd') # -> ['ablaj', 'lskjd'] |
|
""" |
|
if isinstance(other, basestring): |
|
other = Suppress(other) |
|
|
|
if isinstance( other, Suppress ): |
|
if other not in self.ignoreExprs: |
|
self.ignoreExprs.append(other) |
|
else: |
|
self.ignoreExprs.append( Suppress( other.copy() ) ) |
|
return self |
|
|
|
def setDebugActions( self, startAction, successAction, exceptionAction ): |
|
""" |
|
Enable display of debugging messages while doing pattern matching. |
|
""" |
|
self.debugActions = (startAction or _defaultStartDebugAction, |
|
successAction or _defaultSuccessDebugAction, |
|
exceptionAction or _defaultExceptionDebugAction) |
|
self.debug = True |
|
return self |
|
|
|
def setDebug( self, flag=True ): |
|
""" |
|
Enable display of debugging messages while doing pattern matching. |
|
Set C{flag} to True to enable, False to disable. |
|
|
|
Example:: |
|
wd = Word(alphas).setName("alphaword") |
|
integer = Word(nums).setName("numword") |
|
term = wd | integer |
|
|
|
# turn on debugging for wd |
|
wd.setDebug() |
|
|
|
OneOrMore(term).parseString("abc 123 xyz 890") |
|
|
|
prints:: |
|
Match alphaword at loc 0(1,1) |
|
Matched alphaword -> ['abc'] |
|
Match alphaword at loc 3(1,4) |
|
Exception raised:Expected alphaword (at char 4), (line:1, col:5) |
|
Match alphaword at loc 7(1,8) |
|
Matched alphaword -> ['xyz'] |
|
Match alphaword at loc 11(1,12) |
|
Exception raised:Expected alphaword (at char 12), (line:1, col:13) |
|
Match alphaword at loc 15(1,16) |
|
Exception raised:Expected alphaword (at char 15), (line:1, col:16) |
|
|
|
The output shown is that produced by the default debug actions - custom debug actions can be |
|
specified using L{setDebugActions}. Prior to attempting |
|
to match the C{wd} expression, the debugging message C{"Match <exprname> at loc <n>(<line>,<col>)"} |
|
is shown. Then if the parse succeeds, a C{"Matched"} message is shown, or an C{"Exception raised"} |
|
message is shown. Also note the use of L{setName} to assign a human-readable name to the expression, |
|
which makes debugging and exception messages easier to understand - for instance, the default |
|
name created for the C{Word} expression without calling C{setName} is C{"W:(ABCD...)"}. |
|
""" |
|
if flag: |
|
self.setDebugActions( _defaultStartDebugAction, _defaultSuccessDebugAction, _defaultExceptionDebugAction ) |
|
else: |
|
self.debug = False |
|
return self |
|
|
|
def __str__( self ): |
|
return self.name |
|
|
|
def __repr__( self ): |
|
return _ustr(self) |
|
|
|
def streamline( self ): |
|
self.streamlined = True |
|
self.strRepr = None |
|
return self |
|
|
|
def checkRecursion( self, parseElementList ): |
|
pass |
|
|
|
def validate( self, validateTrace=[] ): |
|
""" |
|
Check defined expressions for valid structure, check for infinite recursive definitions. |
|
""" |
|
self.checkRecursion( [] ) |
|
|
|
def parseFile( self, file_or_filename, parseAll=False ): |
|
""" |
|
Execute the parse expression on the given file or filename. |
|
If a filename is specified (instead of a file object), |
|
the entire file is opened, read, and closed before parsing. |
|
""" |
|
try: |
|
file_contents = file_or_filename.read() |
|
except AttributeError: |
|
with open(file_or_filename, "r") as f: |
|
file_contents = f.read() |
|
try: |
|
return self.parseString(file_contents, parseAll) |
|
except ParseBaseException as exc: |
|
if ParserElement.verbose_stacktrace: |
|
raise |
|
else: |
|
# catch and re-raise exception from here, clears out pyparsing internal stack trace |
|
raise exc |
|
|
|
def __eq__(self,other): |
|
if isinstance(other, ParserElement): |
|
return self is other or vars(self) == vars(other) |
|
elif isinstance(other, basestring): |
|
return self.matches(other) |
|
else: |
|
return super(ParserElement,self)==other |
|
|
|
def __ne__(self,other): |
|
return not (self == other) |
|
|
|
def __hash__(self): |
|
return hash(id(self)) |
|
|
|
def __req__(self,other): |
|
return self == other |
|
|
|
def __rne__(self,other): |
|
return not (self == other) |
|
|
|
def matches(self, testString, parseAll=True): |
|
""" |
|
Method for quick testing of a parser against a test string. Good for simple |
|
inline microtests of sub expressions while building up larger parser. |
|
|
|
Parameters: |
|
- testString - to test against this expression for a match |
|
- parseAll - (default=C{True}) - flag to pass to C{L{parseString}} when running tests |
|
|
|
Example:: |
|
expr = Word(nums) |
|
assert expr.matches("100") |
|
""" |
|
try: |
|
self.parseString(_ustr(testString), parseAll=parseAll) |
|
return True |
|
except ParseBaseException: |
|
return False |
|
|
|
def runTests(self, tests, parseAll=True, comment='#', fullDump=True, printResults=True, failureTests=False): |
|
""" |
|
Execute the parse expression on a series of test strings, showing each |
|
test, the parsed results or where the parse failed. Quick and easy way to |
|
run a parse expression against a list of sample strings. |
|
|
|
Parameters: |
|
- tests - a list of separate test strings, or a multiline string of test strings |
|
- parseAll - (default=C{True}) - flag to pass to C{L{parseString}} when running tests |
|
- comment - (default=C{'#'}) - expression for indicating embedded comments in the test |
|
string; pass None to disable comment filtering |
|
- fullDump - (default=C{True}) - dump results as list followed by results names in nested outline; |
|
if False, only dump nested list |
|
- printResults - (default=C{True}) prints test output to stdout |
|
- failureTests - (default=C{False}) indicates if these tests are expected to fail parsing |
|
|
|
Returns: a (success, results) tuple, where success indicates that all tests succeeded |
|
(or failed if C{failureTests} is True), and the results contain a list of lines of each |
|
test's output |
|
|
|
Example:: |
|
number_expr = pyparsing_common.number.copy() |
|
|
|
result = number_expr.runTests(''' |
|
# unsigned integer |
|
100 |
|
# negative integer |
|
-100 |
|
# float with scientific notation |
|
6.02e23 |
|
# integer with scientific notation |
|
1e-12 |
|
''') |
|
print("Success" if result[0] else "Failed!") |
|
|
|
result = number_expr.runTests(''' |
|
# stray character |
|
100Z |
|
# missing leading digit before '.' |
|
-.100 |
|
# too many '.' |
|
3.14.159 |
|
''', failureTests=True) |
|
print("Success" if result[0] else "Failed!") |
|
prints:: |
|
# unsigned integer |
|
100 |
|
[100] |
|
|
|
# negative integer |
|
-100 |
|
[-100] |
|
|
|
# float with scientific notation |
|
6.02e23 |
|
[6.02e+23] |
|
|
|
# integer with scientific notation |
|
1e-12 |
|
[1e-12] |
|
|
|
Success |
|
|
|
# stray character |
|
100Z |
|
^ |
|
FAIL: Expected end of text (at char 3), (line:1, col:4) |
|
|
|
# missing leading digit before '.' |
|
-.100 |
|
^ |
|
FAIL: Expected {real number with scientific notation | real number | signed integer} (at char 0), (line:1, col:1) |
|
|
|
# too many '.' |
|
3.14.159 |
|
^ |
|
FAIL: Expected end of text (at char 4), (line:1, col:5) |
|
|
|
Success |
|
|
|
Each test string must be on a single line. If you want to test a string that spans multiple |
|
lines, create a test like this:: |
|
|
|
expr.runTest(r"this is a test\\n of strings that spans \\n 3 lines") |
|
|
|
(Note that this is a raw string literal, you must include the leading 'r'.) |
|
""" |
|
if isinstance(tests, basestring): |
|
tests = list(map(str.strip, tests.rstrip().splitlines())) |
|
if isinstance(comment, basestring): |
|
comment = Literal(comment) |
|
allResults = [] |
|
comments = [] |
|
success = True |
|
for t in tests: |
|
if comment is not None and comment.matches(t, False) or comments and not t: |
|
comments.append(t) |
|
continue |
|
if not t: |
|
continue |
|
out = ['\n'.join(comments), t] |
|
comments = [] |
|
try: |
|
t = t.replace(r'\n','\n') |
|
result = self.parseString(t, parseAll=parseAll) |
|
out.append(result.dump(full=fullDump)) |
|
success = success and not failureTests |
|
except ParseBaseException as pe: |
|
fatal = "(FATAL)" if isinstance(pe, ParseFatalException) else "" |
|
if '\n' in t: |
|
out.append(line(pe.loc, t)) |
|
out.append(' '*(col(pe.loc,t)-1) + '^' + fatal) |
|
else: |
|
out.append(' '*pe.loc + '^' + fatal) |
|
out.append("FAIL: " + str(pe)) |
|
success = success and failureTests |
|
result = pe |
|
except Exception as exc: |
|
out.append("FAIL-EXCEPTION: " + str(exc)) |
|
success = success and failureTests |
|
result = exc |
|
|
|
if printResults: |
|
if fullDump: |
|
out.append('') |
|
print('\n'.join(out)) |
|
|
|
allResults.append((t, result)) |
|
|
|
return success, allResults |
|
|
|
|
|
class Token(ParserElement): |
|
""" |
|
Abstract C{ParserElement} subclass, for defining atomic matching patterns. |
|
""" |
|
def __init__( self ): |
|
super(Token,self).__init__( savelist=False ) |
|
|
|
|
|
class Empty(Token): |
|
""" |
|
An empty token, will always match. |
|
""" |
|
def __init__( self ): |
|
super(Empty,self).__init__() |
|
self.name = "Empty" |
|
self.mayReturnEmpty = True |
|
self.mayIndexError = False |
|
|
|
|
|
class NoMatch(Token): |
|
""" |
|
A token that will never match. |
|
""" |
|
def __init__( self ): |
|
super(NoMatch,self).__init__() |
|
self.name = "NoMatch" |
|
self.mayReturnEmpty = True |
|
self.mayIndexError = False |
|
self.errmsg = "Unmatchable token" |
|
|
|
def parseImpl( self, instring, loc, doActions=True ): |
|
raise ParseException(instring, loc, self.errmsg, self) |
|
|
|
|
|
class Literal(Token): |
|
""" |
|
Token to exactly match a specified string. |
|
|
|
Example:: |
|
Literal('blah').parseString('blah') # -> ['blah'] |
|
Literal('blah').parseString('blahfooblah') # -> ['blah'] |
|
Literal('blah').parseString('bla') # -> Exception: Expected "blah" |
|
|
|
For case-insensitive matching, use L{CaselessLiteral}. |
|
|
|
For keyword matching (force word break before and after the matched string), |
|
use L{Keyword} or L{CaselessKeyword}. |
|
""" |
|
def __init__( self, matchString ): |
|
super(Literal,self).__init__() |
|
self.match = matchString |
|
self.matchLen = len(matchString) |
|
try: |
|
self.firstMatchChar = matchString[0] |
|
except IndexError: |
|
warnings.warn("null string passed to Literal; use Empty() instead", |
|
SyntaxWarning, stacklevel=2) |
|
self.__class__ = Empty |
|
self.name = '"%s"' % _ustr(self.match) |
|
self.errmsg = "Expected " + self.name |
|
self.mayReturnEmpty = False |
|
self.mayIndexError = False |
|
|
|
# Performance tuning: this routine gets called a *lot* |
|
# if this is a single character match string and the first character matches, |
|
# short-circuit as quickly as possible, and avoid calling startswith |
|
#~ @profile |
|
def parseImpl( self, instring, loc, doActions=True ): |
|
if (instring[loc] == self.firstMatchChar and |
|
(self.matchLen==1 or instring.startswith(self.match,loc)) ): |
|
return loc+self.matchLen, self.match |
|
raise ParseException(instring, loc, self.errmsg, self) |
|
_L = Literal |
|
ParserElement._literalStringClass = Literal |
|
|
|
class Keyword(Token): |
|
""" |
|
Token to exactly match a specified string as a keyword, that is, it must be |
|
immediately followed by a non-keyword character. Compare with C{L{Literal}}: |
|
- C{Literal("if")} will match the leading C{'if'} in C{'ifAndOnlyIf'}. |
|
- C{Keyword("if")} will not; it will only match the leading C{'if'} in C{'if x=1'}, or C{'if(y==2)'} |
|
Accepts two optional constructor arguments in addition to the keyword string: |
|
- C{identChars} is a string of characters that would be valid identifier characters, |
|
defaulting to all alphanumerics + "_" and "$" |
|
- C{caseless} allows case-insensitive matching, default is C{False}. |
|
|
|
Example:: |
|
Keyword("start").parseString("start") # -> ['start'] |
|
Keyword("start").parseString("starting") # -> Exception |
|
|
|
For case-insensitive matching, use L{CaselessKeyword}. |
|
""" |
|
DEFAULT_KEYWORD_CHARS = alphanums+"_$" |
|
|
|
def __init__( self, matchString, identChars=None, caseless=False ): |
|
super(Keyword,self).__init__() |
|
if identChars is None: |
|
identChars = Keyword.DEFAULT_KEYWORD_CHARS |
|
self.match = matchString |
|
self.matchLen = len(matchString) |
|
try: |
|
self.firstMatchChar = matchString[0] |
|
except IndexError: |
|
warnings.warn("null string passed to Keyword; use Empty() instead", |
|
SyntaxWarning, stacklevel=2) |
|
self.name = '"%s"' % self.match |
|
self.errmsg = "Expected " + self.name |
|
self.mayReturnEmpty = False |
|
self.mayIndexError = False |
|
self.caseless = caseless |
|
if caseless: |
|
self.caselessmatch = matchString.upper() |
|
identChars = identChars.upper() |
|
self.identChars = set(identChars) |
|
|
|
def parseImpl( self, instring, loc, doActions=True ): |
|
if self.caseless: |
|
if ( (instring[ loc:loc+self.matchLen ].upper() == self.caselessmatch) and |
|
(loc >= len(instring)-self.matchLen or instring[loc+self.matchLen].upper() not in self.identChars) and |
|
(loc == 0 or instring[loc-1].upper() not in self.identChars) ): |
|
return loc+self.matchLen, self.match |
|
else: |
|
if (instring[loc] == self.firstMatchChar and |
|
(self.matchLen==1 or instring.startswith(self.match,loc)) and |
|
(loc >= len(instring)-self.matchLen or instring[loc+self.matchLen] not in self.identChars) and |
|
(loc == 0 or instring[loc-1] not in self.identChars) ): |
|
return loc+self.matchLen, self.match |
|
raise ParseException(instring, loc, self.errmsg, self) |
|
|
|
def copy(self): |
|
c = super(Keyword,self).copy() |
|
c.identChars = Keyword.DEFAULT_KEYWORD_CHARS |
|
return c |
|
|
|
@staticmethod |
|
def setDefaultKeywordChars( chars ): |
|
"""Overrides the default Keyword chars |
|
""" |
|
Keyword.DEFAULT_KEYWORD_CHARS = chars |
|
|
|
class CaselessLiteral(Literal): |
|
""" |
|
Token to match a specified string, ignoring case of letters. |
|
Note: the matched results will always be in the case of the given |
|
match string, NOT the case of the input text. |
|
|
|
Example:: |
|
OneOrMore(CaselessLiteral("CMD")).parseString("cmd CMD Cmd10") # -> ['CMD', 'CMD', 'CMD'] |
|
|
|
(Contrast with example for L{CaselessKeyword}.) |
|
""" |
|
def __init__( self, matchString ): |
|
super(CaselessLiteral,self).__init__( matchString.upper() ) |
|
# Preserve the defining literal. |
|
self.returnString = matchString |
|
self.name = "'%s'" % self.returnString |
|
self.errmsg = "Expected " + self.name |
|
|
|
def parseImpl( self, instring, loc, doActions=True ): |
|
if instring[ loc:loc+self.matchLen ].upper() == self.match: |
|
return loc+self.matchLen, self.returnString |
|
raise ParseException(instring, loc, self.errmsg, self) |
|
|
|
class CaselessKeyword(Keyword): |
|
""" |
|
Caseless version of L{Keyword}. |
|
|
|
Example:: |
|
OneOrMore(CaselessKeyword("CMD")).parseString("cmd CMD Cmd10") # -> ['CMD', 'CMD'] |
|
|
|
(Contrast with example for L{CaselessLiteral}.) |
|
""" |
|
def __init__( self, matchString, identChars=None ): |
|
super(CaselessKeyword,self).__init__( matchString, identChars, caseless=True ) |
|
|
|
def parseImpl( self, instring, loc, doActions=True ): |
|
if ( (instring[ loc:loc+self.matchLen ].upper() == self.caselessmatch) and |
|
(loc >= len(instring)-self.matchLen or instring[loc+self.matchLen].upper() not in self.identChars) ): |
|
return loc+self.matchLen, self.match |
|
raise ParseException(instring, loc, self.errmsg, self) |
|
|
|
class CloseMatch(Token): |
|
""" |
|
A variation on L{Literal} which matches "close" matches, that is, |
|
strings with at most 'n' mismatching characters. C{CloseMatch} takes parameters: |
|
- C{match_string} - string to be matched |
|
- C{maxMismatches} - (C{default=1}) maximum number of mismatches allowed to count as a match |
|
|
|
The results from a successful parse will contain the matched text from the input string and the following named results: |
|
- C{mismatches} - a list of the positions within the match_string where mismatches were found |
|
- C{original} - the original match_string used to compare against the input string |
|
|
|
If C{mismatches} is an empty list, then the match was an exact match. |
|
|
|
Example:: |
|
patt = CloseMatch("ATCATCGAATGGA") |
|
patt.parseString("ATCATCGAAXGGA") # -> (['ATCATCGAAXGGA'], {'mismatches': [[9]], 'original': ['ATCATCGAATGGA']}) |
|
patt.parseString("ATCAXCGAAXGGA") # -> Exception: Expected 'ATCATCGAATGGA' (with up to 1 mismatches) (at char 0), (line:1, col:1) |
|
|
|
# exact match |
|
patt.parseString("ATCATCGAATGGA") # -> (['ATCATCGAATGGA'], {'mismatches': [[]], 'original': ['ATCATCGAATGGA']}) |
|
|
|
# close match allowing up to 2 mismatches |
|
patt = CloseMatch("ATCATCGAATGGA", maxMismatches=2) |
|
patt.parseString("ATCAXCGAAXGGA") # -> (['ATCAXCGAAXGGA'], {'mismatches': [[4, 9]], 'original': ['ATCATCGAATGGA']}) |
|
""" |
|
def __init__(self, match_string, maxMismatches=1): |
|
super(CloseMatch,self).__init__() |
|
self.name = match_string |
|
self.match_string = match_string |
|
self.maxMismatches = maxMismatches |
|
self.errmsg = "Expected %r (with up to %d mismatches)" % (self.match_string, self.maxMismatches) |
|
self.mayIndexError = False |
|
self.mayReturnEmpty = False |
|
|
|
def parseImpl( self, instring, loc, doActions=True ): |
|
start = loc |
|
instrlen = len(instring) |
|
maxloc = start + len(self.match_string) |
|
|
|
if maxloc <= instrlen: |
|
match_string = self.match_string |
|
match_stringloc = 0 |
|
mismatches = [] |
|
maxMismatches = self.maxMismatches |
|
|
|
for match_stringloc,s_m in enumerate(zip(instring[loc:maxloc], self.match_string)): |
|
src,mat = s_m |
|
if src != mat: |
|
mismatches.append(match_stringloc) |
|
if len(mismatches) > maxMismatches: |
|
break |
|
else: |
|
loc = match_stringloc + 1 |
|
results = ParseResults([instring[start:loc]]) |
|
results['original'] = self.match_string |
|
results['mismatches'] = mismatches |
|
return loc, results |
|
|
|
raise ParseException(instring, loc, self.errmsg, self) |
|
|
|
|
|
class Word(Token): |
|
""" |
|
Token for matching words composed of allowed character sets. |
|
Defined with string containing all allowed initial characters, |
|
an optional string containing allowed body characters (if omitted, |
|
defaults to the initial character set), and an optional minimum, |
|
maximum, and/or exact length. The default value for C{min} is 1 (a |
|
minimum value < 1 is not valid); the default values for C{max} and C{exact} |
|
are 0, meaning no maximum or exact length restriction. An optional |
|
C{excludeChars} parameter can list characters that might be found in |
|
the input C{bodyChars} string; useful to define a word of all printables |
|
except for one or two characters, for instance. |
|
|
|
L{srange} is useful for defining custom character set strings for defining |
|
C{Word} expressions, using range notation from regular expression character sets. |
|
|
|
A common mistake is to use C{Word} to match a specific literal string, as in |
|
C{Word("Address")}. Remember that C{Word} uses the string argument to define |
|
I{sets} of matchable characters. This expression would match "Add", "AAA", |
|
"dAred", or any other word made up of the characters 'A', 'd', 'r', 'e', and 's'. |
|
To match an exact literal string, use L{Literal} or L{Keyword}. |
|
|
|
pyparsing includes helper strings for building Words: |
|
- L{alphas} |
|
- L{nums} |
|
- L{alphanums} |
|
- L{hexnums} |
|
- L{alphas8bit} (alphabetic characters in ASCII range 128-255 - accented, tilded, umlauted, etc.) |
|
- L{punc8bit} (non-alphabetic characters in ASCII range 128-255 - currency, symbols, superscripts, diacriticals, etc.) |
|
- L{printables} (any non-whitespace character) |
|
|
|
Example:: |
|
# a word composed of digits |
|
integer = Word(nums) # equivalent to Word("0123456789") or Word(srange("0-9")) |
|
|
|
# a word with a leading capital, and zero or more lowercase |
|
capital_word = Word(alphas.upper(), alphas.lower()) |
|
|
|
# hostnames are alphanumeric, with leading alpha, and '-' |
|
hostname = Word(alphas, alphanums+'-') |
|
|
|
# roman numeral (not a strict parser, accepts invalid mix of characters) |
|
roman = Word("IVXLCDM") |
|
|
|
# any string of non-whitespace characters, except for ',' |
|
csv_value = Word(printables, excludeChars=",") |
|
""" |
|
def __init__( self, initChars, bodyChars=None, min=1, max=0, exact=0, asKeyword=False, excludeChars=None ): |
|
super(Word,self).__init__() |
|
if excludeChars: |
|
initChars = ''.join(c for c in initChars if c not in excludeChars) |
|
if bodyChars: |
|
bodyChars = ''.join(c for c in bodyChars if c not in excludeChars) |
|
self.initCharsOrig = initChars |
|
self.initChars = set(initChars) |
|
if bodyChars : |
|
self.bodyCharsOrig = bodyChars |
|
self.bodyChars = set(bodyChars) |
|
else: |
|
self.bodyCharsOrig = initChars |
|
self.bodyChars = set(initChars) |
|
|
|
self.maxSpecified = max > 0 |
|
|
|
if min < 1: |
|
raise ValueError("cannot specify a minimum length < 1; use Optional(Word()) if zero-length word is permitted") |
|
|
|
self.minLen = min |
|
|
|
if max > 0: |
|
self.maxLen = max |
|
else: |
|
self.maxLen = _MAX_INT |
|
|
|
if exact > 0: |
|
self.maxLen = exact |
|
self.minLen = exact |
|
|
|
self.name = _ustr(self) |
|
self.errmsg = "Expected " + self.name |
|
self.mayIndexError = False |
|
self.asKeyword = asKeyword |
|
|
|
if ' ' not in self.initCharsOrig+self.bodyCharsOrig and (min==1 and max==0 and exact==0): |
|
if self.bodyCharsOrig == self.initCharsOrig: |
|
self.reString = "[%s]+" % _escapeRegexRangeChars(self.initCharsOrig) |
|
elif len(self.initCharsOrig) == 1: |
|
self.reString = "%s[%s]*" % \ |
|
(re.escape(self.initCharsOrig), |
|
_escapeRegexRangeChars(self.bodyCharsOrig),) |
|
else: |
|
self.reString = "[%s][%s]*" % \ |
|
(_escapeRegexRangeChars(self.initCharsOrig), |
|
_escapeRegexRangeChars(self.bodyCharsOrig),) |
|
if self.asKeyword: |
|
self.reString = r"\b"+self.reString+r"\b" |
|
try: |
|
self.re = re.compile( self.reString ) |
|
except Exception: |
|
self.re = None |
|
|
|
def parseImpl( self, instring, loc, doActions=True ): |
|
if self.re: |
|
result = self.re.match(instring,loc) |
|
if not result: |
|
raise ParseException(instring, loc, self.errmsg, self) |
|
|
|
loc = result.end() |
|
return loc, result.group() |
|
|
|
if not(instring[ loc ] in self.initChars): |
|
raise ParseException(instring, loc, self.errmsg, self) |
|
|
|
start = loc |
|
loc += 1 |
|
instrlen = len(instring) |
|
bodychars = self.bodyChars |
|
maxloc = start + self.maxLen |
|
maxloc = min( maxloc, instrlen ) |
|
while loc < maxloc and instring[loc] in bodychars: |
|
loc += 1 |
|
|
|
throwException = False |
|
if loc - start < self.minLen: |
|
throwException = True |
|
if self.maxSpecified and loc < instrlen and instring[loc] in bodychars: |
|
throwException = True |
|
if self.asKeyword: |
|
if (start>0 and instring[start-1] in bodychars) or (loc<instrlen and instring[loc] in bodychars): |
|
throwException = True |
|
|
|
if throwException: |
|
raise ParseException(instring, loc, self.errmsg, self) |
|
|
|
return loc, instring[start:loc] |
|
|
|
def __str__( self ): |
|
try: |
|
return super(Word,self).__str__() |
|
except Exception: |
|
pass |
|
|
|
|
|
if self.strRepr is None: |
|
|
|
def charsAsStr(s): |
|
if len(s)>4: |
|
return s[:4]+"..." |
|
else: |
|
return s |
|
|
|
if ( self.initCharsOrig != self.bodyCharsOrig ): |
|
self.strRepr = "W:(%s,%s)" % ( charsAsStr(self.initCharsOrig), charsAsStr(self.bodyCharsOrig) ) |
|
else: |
|
self.strRepr = "W:(%s)" % charsAsStr(self.initCharsOrig) |
|
|
|
return self.strRepr |
|
|
|
|
|
class Regex(Token): |
|
r""" |
|
Token for matching strings that match a given regular expression. |
|
Defined with string specifying the regular expression in a form recognized by the inbuilt Python re module. |
|
If the given regex contains named groups (defined using C{(?P<name>...)}), these will be preserved as |
|
named parse results. |
|
|
|
Example:: |
|
realnum = Regex(r"[+-]?\d+\.\d*") |
|
date = Regex(r'(?P<year>\d{4})-(?P<month>\d\d?)-(?P<day>\d\d?)') |
|
# ref: http://stackoverflow.com/questions/267399/how-do-you-match-only-valid-roman-numerals-with-a-regular-expression |
|
roman = Regex(r"M{0,4}(CM|CD|D?C{0,3})(XC|XL|L?X{0,3})(IX|IV|V?I{0,3})") |
|
""" |
|
compiledREtype = type(re.compile("[A-Z]")) |
|
def __init__( self, pattern, flags=0): |
|
"""The parameters C{pattern} and C{flags} are passed to the C{re.compile()} function as-is. See the Python C{re} module for an explanation of the acceptable patterns and flags.""" |
|
super(Regex,self).__init__() |
|
|
|
if isinstance(pattern, basestring): |
|
if not pattern: |
|
warnings.warn("null string passed to Regex; use Empty() instead", |
|
SyntaxWarning, stacklevel=2) |
|
|
|
self.pattern = pattern |
|
self.flags = flags |
|
|
|
try: |
|
self.re = re.compile(self.pattern, self.flags) |
|
self.reString = self.pattern |
|
except sre_constants.error: |
|
warnings.warn("invalid pattern (%s) passed to Regex" % pattern, |
|
SyntaxWarning, stacklevel=2) |
|
raise |
|
|
|
elif isinstance(pattern, Regex.compiledREtype): |
|
self.re = pattern |
|
self.pattern = \ |
|
self.reString = str(pattern) |
|
self.flags = flags |
|
|
|
else: |
|
raise ValueError("Regex may only be constructed with a string or a compiled RE object") |
|
|
|
self.name = _ustr(self) |
|
self.errmsg = "Expected " + self.name |
|
self.mayIndexError = False |
|
self.mayReturnEmpty = True |
|
|
|
def parseImpl( self, instring, loc, doActions=True ): |
|
result = self.re.match(instring,loc) |
|
if not result: |
|
raise ParseException(instring, loc, self.errmsg, self) |
|
|
|
loc = result.end() |
|
d = result.groupdict() |
|
ret = ParseResults(result.group()) |
|
if d: |
|
for k in d: |
|
ret[k] = d[k] |
|
return loc,ret |
|
|
|
def __str__( self ): |
|
try: |
|
return super(Regex,self).__str__() |
|
except Exception: |
|
pass |
|
|
|
if self.strRepr is None: |
|
self.strRepr = "Re:(%s)" % repr(self.pattern) |
|
|
|
return self.strRepr |
|
|
|
|
|
class QuotedString(Token): |
|
r""" |
|
Token for matching strings that are delimited by quoting characters. |
|
|
|
Defined with the following parameters: |
|
- quoteChar - string of one or more characters defining the quote delimiting string |
|
- escChar - character to escape quotes, typically backslash (default=C{None}) |
|
- escQuote - special quote sequence to escape an embedded quote string (such as SQL's "" to escape an embedded ") (default=C{None}) |
|
- multiline - boolean indicating whether quotes can span multiple lines (default=C{False}) |
|
- unquoteResults - boolean indicating whether the matched text should be unquoted (default=C{True}) |
|
- endQuoteChar - string of one or more characters defining the end of the quote delimited string (default=C{None} => same as quoteChar) |
|
- convertWhitespaceEscapes - convert escaped whitespace (C{'\t'}, C{'\n'}, etc.) to actual whitespace (default=C{True}) |
|
|
|
Example:: |
|
qs = QuotedString('"') |
|
print(qs.searchString('lsjdf "This is the quote" sldjf')) |
|
complex_qs = QuotedString('{{', endQuoteChar='}}') |
|
print(complex_qs.searchString('lsjdf {{This is the "quote"}} sldjf')) |
|
sql_qs = QuotedString('"', escQuote='""') |
|
print(sql_qs.searchString('lsjdf "This is the quote with ""embedded"" quotes" sldjf')) |
|
prints:: |
|
[['This is the quote']] |
|
[['This is the "quote"']] |
|
[['This is the quote with "embedded" quotes']] |
|
""" |
|
def __init__( self, quoteChar, escChar=None, escQuote=None, multiline=False, unquoteResults=True, endQuoteChar=None, convertWhitespaceEscapes=True): |
|
super(QuotedString,self).__init__() |
|
|
|
# remove white space from quote chars - wont work anyway |
|
quoteChar = quoteChar.strip() |
|
if not quoteChar: |
|
warnings.warn("quoteChar cannot be the empty string",SyntaxWarning,stacklevel=2) |
|
raise SyntaxError() |
|
|
|
if endQuoteChar is None: |
|
endQuoteChar = quoteChar |
|
else: |
|
endQuoteChar = endQuoteChar.strip() |
|
if not endQuoteChar: |
|
warnings.warn("endQuoteChar cannot be the empty string",SyntaxWarning,stacklevel=2) |
|
raise SyntaxError() |
|
|
|
self.quoteChar = quoteChar |
|
self.quoteCharLen = len(quoteChar) |
|
self.firstQuoteChar = quoteChar[0] |
|
self.endQuoteChar = endQuoteChar |
|
self.endQuoteCharLen = len(endQuoteChar) |
|
self.escChar = escChar |
|
self.escQuote = escQuote |
|
self.unquoteResults = unquoteResults |
|
self.convertWhitespaceEscapes = convertWhitespaceEscapes |
|
|
|
if multiline: |
|
self.flags = re.MULTILINE | re.DOTALL |
|
self.pattern = r'%s(?:[^%s%s]' % \ |
|
( re.escape(self.quoteChar), |
|
_escapeRegexRangeChars(self.endQuoteChar[0]), |
|
(escChar is not None and _escapeRegexRangeChars(escChar) or '') ) |
|
else: |
|
self.flags = 0 |
|
self.pattern = r'%s(?:[^%s\n\r%s]' % \ |
|
( re.escape(self.quoteChar), |
|
_escapeRegexRangeChars(self.endQuoteChar[0]), |
|
(escChar is not None and _escapeRegexRangeChars(escChar) or '') ) |
|
if len(self.endQuoteChar) > 1: |
|
self.pattern += ( |
|
'|(?:' + ')|(?:'.join("%s[^%s]" % (re.escape(self.endQuoteChar[:i]), |
|
_escapeRegexRangeChars(self.endQuoteChar[i])) |
|
for i in range(len(self.endQuoteChar)-1,0,-1)) + ')' |
|
) |
|
if escQuote: |
|
self.pattern += (r'|(?:%s)' % re.escape(escQuote)) |
|
if escChar: |
|
self.pattern += (r'|(?:%s.)' % re.escape(escChar)) |
|
self.escCharReplacePattern = re.escape(self.escChar)+"(.)" |
|
self.pattern += (r')*%s' % re.escape(self.endQuoteChar)) |
|
|
|
try: |
|
self.re = re.compile(self.pattern, self.flags) |
|
self.reString = self.pattern |
|
except sre_constants.error: |
|
warnings.warn("invalid pattern (%s) passed to Regex" % self.pattern, |
|
SyntaxWarning, stacklevel=2) |
|
raise |
|
|
|
self.name = _ustr(self) |
|
self.errmsg = "Expected " + self.name |
|
self.mayIndexError = False |
|
self.mayReturnEmpty = True |
|
|
|
def parseImpl( self, instring, loc, doActions=True ): |
|
result = instring[loc] == self.firstQuoteChar and self.re.match(instring,loc) or None |
|
if not result: |
|
raise ParseException(instring, loc, self.errmsg, self) |
|
|
|
loc = result.end() |
|
ret = result.group() |
|
|
|
if self.unquoteResults: |
|
|
|
# strip off quotes |
|
ret = ret[self.quoteCharLen:-self.endQuoteCharLen] |
|
|
|
if isinstance(ret,basestring): |
|
# replace escaped whitespace |
|
if '\\' in ret and self.convertWhitespaceEscapes: |
|
ws_map = { |
|
r'\t' : '\t', |
|
r'\n' : '\n', |
|
r'\f' : '\f', |
|
r'\r' : '\r', |
|
} |
|
for wslit,wschar in ws_map.items(): |
|
ret = ret.replace(wslit, wschar) |
|
|
|
# replace escaped characters |
|
if self.escChar: |
|
ret = re.sub(self.escCharReplacePattern, r"\g<1>", ret) |
|
|
|
# replace escaped quotes |
|
if self.escQuote: |
|
ret = ret.replace(self.escQuote, self.endQuoteChar) |
|
|
|
return loc, ret |
|
|
|
def __str__( self ): |
|
try: |
|
return super(QuotedString,self).__str__() |
|
except Exception: |
|
pass |
|
|
|
if self.strRepr is None: |
|
self.strRepr = "quoted string, starting with %s ending with %s" % (self.quoteChar, self.endQuoteChar) |
|
|
|
return self.strRepr |
|
|
|
|
|
class CharsNotIn(Token): |
|
""" |
|
Token for matching words composed of characters I{not} in a given set (will |
|
include whitespace in matched characters if not listed in the provided exclusion set - see example). |
|
Defined with string containing all disallowed characters, and an optional |
|
minimum, maximum, and/or exact length. The default value for C{min} is 1 (a |
|
minimum value < 1 is not valid); the default values for C{max} and C{exact} |
|
are 0, meaning no maximum or exact length restriction. |
|
|
|
Example:: |
|
# define a comma-separated-value as anything that is not a ',' |
|
csv_value = CharsNotIn(',') |
|
print(delimitedList(csv_value).parseString("dkls,lsdkjf,s12 34,@!#,213")) |
|
prints:: |
|
['dkls', 'lsdkjf', 's12 34', '@!#', '213'] |
|
""" |
|
def __init__( self, notChars, min=1, max=0, exact=0 ): |
|
super(CharsNotIn,self).__init__() |
|
self.skipWhitespace = False |
|
self.notChars = notChars |
|
|
|
if min < 1: |
|
raise ValueError("cannot specify a minimum length < 1; use Optional(CharsNotIn()) if zero-length char group is permitted") |
|
|
|
self.minLen = min |
|
|
|
if max > 0: |
|
self.maxLen = max |
|
else: |
|
self.maxLen = _MAX_INT |
|
|
|
if exact > 0: |
|
self.maxLen = exact |
|
self.minLen = exact |
|
|
|
self.name = _ustr(self) |
|
self.errmsg = "Expected " + self.name |
|
self.mayReturnEmpty = ( self.minLen == 0 ) |
|
self.mayIndexError = False |
|
|
|
def parseImpl( self, instring, loc, doActions=True ): |
|
if instring[loc] in self.notChars: |
|
raise ParseException(instring, loc, self.errmsg, self) |
|
|
|
start = loc |
|
loc += 1 |
|
notchars = self.notChars |
|
maxlen = min( start+self.maxLen, len(instring) ) |
|
while loc < maxlen and \ |
|
(instring[loc] not in notchars): |
|
loc += 1 |
|
|
|
if loc - start < self.minLen: |
|
raise ParseException(instring, loc, self.errmsg, self) |
|
|
|
return loc, instring[start:loc] |
|
|
|
def __str__( self ): |
|
try: |
|
return super(CharsNotIn, self).__str__() |
|
except Exception: |
|
pass |
|
|
|
if self.strRepr is None: |
|
if len(self.notChars) > 4: |
|
self.strRepr = "!W:(%s...)" % self.notChars[:4] |
|
else: |
|
self.strRepr = "!W:(%s)" % self.notChars |
|
|
|
return self.strRepr |
|
|
|
class White(Token): |
|
""" |
|
Special matching class for matching whitespace. Normally, whitespace is ignored |
|
by pyparsing grammars. This class is included when some whitespace structures |
|
are significant. Define with a string containing the whitespace characters to be |
|
matched; default is C{" \\t\\r\\n"}. Also takes optional C{min}, C{max}, and C{exact} arguments, |
|
as defined for the C{L{Word}} class. |
|
""" |
|
whiteStrs = { |
|
" " : "<SPC>", |
|
"\t": "<TAB>", |
|
"\n": "<LF>", |
|
"\r": "<CR>", |
|
"\f": "<FF>", |
|
} |
|
def __init__(self, ws=" \t\r\n", min=1, max=0, exact=0): |
|
super(White,self).__init__() |
|
self.matchWhite = ws |
|
self.setWhitespaceChars( "".join(c for c in self.whiteChars if c not in self.matchWhite) ) |
|
#~ self.leaveWhitespace() |
|
self.name = ("".join(White.whiteStrs[c] for c in self.matchWhite)) |
|
self.mayReturnEmpty = True |
|
self.errmsg = "Expected " + self.name |
|
|
|
self.minLen = min |
|
|
|
if max > 0: |
|
self.maxLen = max |
|
else: |
|
self.maxLen = _MAX_INT |
|
|
|
if exact > 0: |
|
self.maxLen = exact |
|
self.minLen = exact |
|
|
|
def parseImpl( self, instring, loc, doActions=True ): |
|
if not(instring[ loc ] in self.matchWhite): |
|
raise ParseException(instring, loc, self.errmsg, self) |
|
start = loc |
|
loc += 1 |
|
maxloc = start + self.maxLen |
|
maxloc = min( maxloc, len(instring) ) |
|
while loc < maxloc and instring[loc] in self.matchWhite: |
|
loc += 1 |
|
|
|
if loc - start < self.minLen: |
|
raise ParseException(instring, loc, self.errmsg, self) |
|
|
|
return loc, instring[start:loc] |
|
|
|
|
|
class _PositionToken(Token): |
|
def __init__( self ): |
|
super(_PositionToken,self).__init__() |
|
self.name=self.__class__.__name__ |
|
self.mayReturnEmpty = True |
|
self.mayIndexError = False |
|
|
|
class GoToColumn(_PositionToken): |
|
""" |
|
Token to advance to a specific column of input text; useful for tabular report scraping. |
|
""" |
|
def __init__( self, colno ): |
|
super(GoToColumn,self).__init__() |
|
self.col = colno |
|
|
|
def preParse( self, instring, loc ): |
|
if col(loc,instring) != self.col: |
|
instrlen = len(instring) |
|
if self.ignoreExprs: |
|
loc = self._skipIgnorables( instring, loc ) |
|
while loc < instrlen and instring[loc].isspace() and col( loc, instring ) != self.col : |
|
loc += 1 |
|
return loc |
|
|
|
def parseImpl( self, instring, loc, doActions=True ): |
|
thiscol = col( loc, instring ) |
|
if thiscol > self.col: |
|
raise ParseException( instring, loc, "Text not in expected column", self ) |
|
newloc = loc + self.col - thiscol |
|
ret = instring[ loc: newloc ] |
|
return newloc, ret |
|
|
|
|
|
class LineStart(_PositionToken): |
|
""" |
|
Matches if current position is at the beginning of a line within the parse string |
|
|
|
Example:: |
|
|
|
test = '''\ |
|
AAA this line |
|
AAA and this line |
|
AAA but not this one |
|
B AAA and definitely not this one |
|
''' |
|
|
|
for t in (LineStart() + 'AAA' + restOfLine).searchString(test): |
|
print(t) |
|
|
|
Prints:: |
|
['AAA', ' this line'] |
|
['AAA', ' and this line'] |
|
|
|
""" |
|
def __init__( self ): |
|
super(LineStart,self).__init__() |
|
self.errmsg = "Expected start of line" |
|
|
|
def parseImpl( self, instring, loc, doActions=True ): |
|
if col(loc, instring) == 1: |
|
return loc, [] |
|
raise ParseException(instring, loc, self.errmsg, self) |
|
|
|
class LineEnd(_PositionToken): |
|
""" |
|
Matches if current position is at the end of a line within the parse string |
|
""" |
|
def __init__( self ): |
|
super(LineEnd,self).__init__() |
|
self.setWhitespaceChars( ParserElement.DEFAULT_WHITE_CHARS.replace("\n","") ) |
|
self.errmsg = "Expected end of line" |
|
|
|
def parseImpl( self, instring, loc, doActions=True ): |
|
if loc<len(instring): |
|
if instring[loc] == "\n": |
|
return loc+1, "\n" |
|
else: |
|
raise ParseException(instring, loc, self.errmsg, self) |
|
elif loc == len(instring): |
|
return loc+1, [] |
|
else: |
|
raise ParseException(instring, loc, self.errmsg, self) |
|
|
|
class StringStart(_PositionToken): |
|
""" |
|
Matches if current position is at the beginning of the parse string |
|
""" |
|
def __init__( self ): |
|
super(StringStart,self).__init__() |
|
self.errmsg = "Expected start of text" |
|
|
|
def parseImpl( self, instring, loc, doActions=True ): |
|
if loc != 0: |
|
# see if entire string up to here is just whitespace and ignoreables |
|
if loc != self.preParse( instring, 0 ): |
|
raise ParseException(instring, loc, self.errmsg, self) |
|
return loc, [] |
|
|
|
class StringEnd(_PositionToken): |
|
""" |
|
Matches if current position is at the end of the parse string |
|
""" |
|
def __init__( self ): |
|
super(StringEnd,self).__init__() |
|
self.errmsg = "Expected end of text" |
|
|
|
def parseImpl( self, instring, loc, doActions=True ): |
|
if loc < len(instring): |
|
raise ParseException(instring, loc, self.errmsg, self) |
|
elif loc == len(instring): |
|
return loc+1, [] |
|
elif loc > len(instring): |
|
return loc, [] |
|
else: |
|
raise ParseException(instring, loc, self.errmsg, self) |
|
|
|
class WordStart(_PositionToken): |
|
""" |
|
Matches if the current position is at the beginning of a Word, and |
|
is not preceded by any character in a given set of C{wordChars} |
|
(default=C{printables}). To emulate the C{\b} behavior of regular expressions, |
|
use C{WordStart(alphanums)}. C{WordStart} will also match at the beginning of |
|
the string being parsed, or at the beginning of a line. |
|
""" |
|
def __init__(self, wordChars = printables): |
|
super(WordStart,self).__init__() |
|
self.wordChars = set(wordChars) |
|
self.errmsg = "Not at the start of a word" |
|
|
|
def parseImpl(self, instring, loc, doActions=True ): |
|
if loc != 0: |
|
if (instring[loc-1] in self.wordChars or |
|
instring[loc] not in self.wordChars): |
|
raise ParseException(instring, loc, self.errmsg, self) |
|
return loc, [] |
|
|
|
class WordEnd(_PositionToken): |
|
""" |
|
Matches if the current position is at the end of a Word, and |
|
is not followed by any character in a given set of C{wordChars} |
|
(default=C{printables}). To emulate the C{\b} behavior of regular expressions, |
|
use C{WordEnd(alphanums)}. C{WordEnd} will also match at the end of |
|
the string being parsed, or at the end of a line. |
|
""" |
|
def __init__(self, wordChars = printables): |
|
super(WordEnd,self).__init__() |
|
self.wordChars = set(wordChars) |
|
self.skipWhitespace = False |
|
self.errmsg = "Not at the end of a word" |
|
|
|
def parseImpl(self, instring, loc, doActions=True ): |
|
instrlen = len(instring) |
|
if instrlen>0 and loc<instrlen: |
|
if (instring[loc] in self.wordChars or |
|
instring[loc-1] not in self.wordChars): |
|
raise ParseException(instring, loc, self.errmsg, self) |
|
return loc, [] |
|
|
|
|
|
class ParseExpression(ParserElement): |
|
""" |
|
Abstract subclass of ParserElement, for combining and post-processing parsed tokens. |
|
""" |
|
def __init__( self, exprs, savelist = False ): |
|
super(ParseExpression,self).__init__(savelist) |
|
if isinstance( exprs, _generatorType ): |
|
exprs = list(exprs) |
|
|
|
if isinstance( exprs, basestring ): |
|
self.exprs = [ ParserElement._literalStringClass( exprs ) ] |
|
elif isinstance( exprs, Iterable ): |
|
exprs = list(exprs) |
|
# if sequence of strings provided, wrap with Literal |
|
if all(isinstance(expr, basestring) for expr in exprs): |
|
exprs = map(ParserElement._literalStringClass, exprs) |
|
self.exprs = list(exprs) |
|
else: |
|
try: |
|
self.exprs = list( exprs ) |
|
except TypeError: |
|
self.exprs = [ exprs ] |
|
self.callPreparse = False |
|
|
|
def __getitem__( self, i ): |
|
return self.exprs[i] |
|
|
|
def append( self, other ): |
|
self.exprs.append( other ) |
|
self.strRepr = None |
|
return self |
|
|
|
def leaveWhitespace( self ): |
|
"""Extends C{leaveWhitespace} defined in base class, and also invokes C{leaveWhitespace} on |
|
all contained expressions.""" |
|
self.skipWhitespace = False |
|
self.exprs = [ e.copy() for e in self.exprs ] |
|
for e in self.exprs: |
|
e.leaveWhitespace() |
|
return self |
|
|
|
def ignore( self, other ): |
|
if isinstance( other, Suppress ): |
|
if other not in self.ignoreExprs: |
|
super( ParseExpression, self).ignore( other ) |
|
for e in self.exprs: |
|
e.ignore( self.ignoreExprs[-1] ) |
|
else: |
|
super( ParseExpression, self).ignore( other ) |
|
for e in self.exprs: |
|
e.ignore( self.ignoreExprs[-1] ) |
|
return self |
|
|
|
def __str__( self ): |
|
try: |
|
return super(ParseExpression,self).__str__() |
|
except Exception: |
|
pass |
|
|
|
if self.strRepr is None: |
|
self.strRepr = "%s:(%s)" % ( self.__class__.__name__, _ustr(self.exprs) ) |
|
return self.strRepr |
|
|
|
def streamline( self ): |
|
super(ParseExpression,self).streamline() |
|
|
|
for e in self.exprs: |
|
e.streamline() |
|
|
|
# collapse nested And's of the form And( And( And( a,b), c), d) to And( a,b,c,d ) |
|
# but only if there are no parse actions or resultsNames on the nested And's |
|
# (likewise for Or's and MatchFirst's) |
|
if ( len(self.exprs) == 2 ): |
|
other = self.exprs[0] |
|
if ( isinstance( other, self.__class__ ) and |
|
not(other.parseAction) and |
|
other.resultsName is None and |
|
not other.debug ): |
|
self.exprs = other.exprs[:] + [ self.exprs[1] ] |
|
self.strRepr = None |
|
self.mayReturnEmpty |= other.mayReturnEmpty |
|
self.mayIndexError |= other.mayIndexError |
|
|
|
other = self.exprs[-1] |
|
if ( isinstance( other, self.__class__ ) and |
|
not(other.parseAction) and |
|
other.resultsName is None and |
|
not other.debug ): |
|
self.exprs = self.exprs[:-1] + other.exprs[:] |
|
self.strRepr = None |
|
self.mayReturnEmpty |= other.mayReturnEmpty |
|
self.mayIndexError |= other.mayIndexError |
|
|
|
self.errmsg = "Expected " + _ustr(self) |
|
|
|
return self |
|
|
|
def setResultsName( self, name, listAllMatches=False ): |
|
ret = super(ParseExpression,self).setResultsName(name,listAllMatches) |
|
return ret |
|
|
|
def validate( self, validateTrace=[] ): |
|
tmp = validateTrace[:]+[self] |
|
for e in self.exprs: |
|
e.validate(tmp) |
|
self.checkRecursion( [] ) |
|
|
|
def copy(self): |
|
ret = super(ParseExpression,self).copy() |
|
ret.exprs = [e.copy() for e in self.exprs] |
|
return ret |
|
|
|
class And(ParseExpression): |
|
""" |
|
Requires all given C{ParseExpression}s to be found in the given order. |
|
Expressions may be separated by whitespace. |
|
May be constructed using the C{'+'} operator. |
|
May also be constructed using the C{'-'} operator, which will suppress backtracking. |
|
|
|
Example:: |
|
integer = Word(nums) |
|
name_expr = OneOrMore(Word(alphas)) |
|
|
|
expr = And([integer("id"),name_expr("name"),integer("age")]) |
|
# more easily written as: |
|
expr = integer("id") + name_expr("name") + integer("age") |
|
""" |
|
|
|
class _ErrorStop(Empty): |
|
def __init__(self, *args, **kwargs): |
|
super(And._ErrorStop,self).__init__(*args, **kwargs) |
|
self.name = '-' |
|
self.leaveWhitespace() |
|
|
|
def __init__( self, exprs, savelist = True ): |
|
super(And,self).__init__(exprs, savelist) |
|
self.mayReturnEmpty = all(e.mayReturnEmpty for e in self.exprs) |
|
self.setWhitespaceChars( self.exprs[0].whiteChars ) |
|
self.skipWhitespace = self.exprs[0].skipWhitespace |
|
self.callPreparse = True |
|
|
|
def parseImpl( self, instring, loc, doActions=True ): |
|
# pass False as last arg to _parse for first element, since we already |
|
# pre-parsed the string as part of our And pre-parsing |
|
loc, resultlist = self.exprs[0]._parse( instring, loc, doActions, callPreParse=False ) |
|
errorStop = False |
|
for e in self.exprs[1:]: |
|
if isinstance(e, And._ErrorStop): |
|
errorStop = True |
|
continue |
|
if errorStop: |
|
try: |
|
loc, exprtokens = e._parse( instring, loc, doActions ) |
|
except ParseSyntaxException: |
|
raise |
|
except ParseBaseException as pe: |
|
pe.__traceback__ = None |
|
raise ParseSyntaxException._from_exception(pe) |
|
except IndexError: |
|
raise ParseSyntaxException(instring, len(instring), self.errmsg, self) |
|
else: |
|
loc, exprtokens = e._parse( instring, loc, doActions ) |
|
if exprtokens or exprtokens.haskeys(): |
|
resultlist += exprtokens |
|
return loc, resultlist |
|
|
|
def __iadd__(self, other ): |
|
if isinstance( other, basestring ): |
|
other = ParserElement._literalStringClass( other ) |
|
return self.append( other ) #And( [ self, other ] ) |
|
|
|
def checkRecursion( self, parseElementList ): |
|
subRecCheckList = parseElementList[:] + [ self ] |
|
for e in self.exprs: |
|
e.checkRecursion( subRecCheckList ) |
|
if not e.mayReturnEmpty: |
|
break |
|
|
|
def __str__( self ): |
|
if hasattr(self,"name"): |
|
return self.name |
|
|
|
if self.strRepr is None: |
|
self.strRepr = "{" + " ".join(_ustr(e) for e in self.exprs) + "}" |
|
|
|
return self.strRepr |
|
|
|
|
|
class Or(ParseExpression): |
|
""" |
|
Requires that at least one C{ParseExpression} is found. |
|
If two expressions match, the expression that matches the longest string will be used. |
|
May be constructed using the C{'^'} operator. |
|
|
|
Example:: |
|
# construct Or using '^' operator |
|
|
|
number = Word(nums) ^ Combine(Word(nums) + '.' + Word(nums)) |
|
print(number.searchString("123 3.1416 789")) |
|
prints:: |
|
[['123'], ['3.1416'], ['789']] |
|
""" |
|
def __init__( self, exprs, savelist = False ): |
|
super(Or,self).__init__(exprs, savelist) |
|
if self.exprs: |
|
self.mayReturnEmpty = any(e.mayReturnEmpty for e in self.exprs) |
|
else: |
|
self.mayReturnEmpty = True |
|
|
|
def parseImpl( self, instring, loc, doActions=True ): |
|
maxExcLoc = -1 |
|
maxException = None |
|
matches = [] |
|
for e in self.exprs: |
|
try: |
|
loc2 = e.tryParse( instring, loc ) |
|
except ParseException as err: |
|
err.__traceback__ = None |
|
if err.loc > maxExcLoc: |
|
maxException = err |
|
maxExcLoc = err.loc |
|
except IndexError: |
|
if len(instring) > maxExcLoc: |
|
maxException = ParseException(instring,len(instring),e.errmsg,self) |
|
maxExcLoc = len(instring) |
|
else: |
|
# save match among all matches, to retry longest to shortest |
|
matches.append((loc2, e)) |
|
|
|
if matches: |
|
matches.sort(key=lambda x: -x[0]) |
|
for _,e in matches: |
|
try: |
|
return e._parse( instring, loc, doActions ) |
|
except ParseException as err: |
|
err.__traceback__ = None |
|
if err.loc > maxExcLoc: |
|
maxException = err |
|
maxExcLoc = err.loc |
|
|
|
if maxException is not None: |
|
maxException.msg = self.errmsg |
|
raise maxException |
|
else: |
|
raise ParseException(instring, loc, "no defined alternatives to match", self) |
|
|
|
|
|
def __ixor__(self, other ): |
|
if isinstance( other, basestring ): |
|
other = ParserElement._literalStringClass( other ) |
|
return self.append( other ) #Or( [ self, other ] ) |
|
|
|
def __str__( self ): |
|
if hasattr(self,"name"): |
|
return self.name |
|
|
|
if self.strRepr is None: |
|
self.strRepr = "{" + " ^ ".join(_ustr(e) for e in self.exprs) + "}" |
|
|
|
return self.strRepr |
|
|
|
def checkRecursion( self, parseElementList ): |
|
subRecCheckList = parseElementList[:] + [ self ] |
|
for e in self.exprs: |
|
e.checkRecursion( subRecCheckList ) |
|
|
|
|
|
class MatchFirst(ParseExpression): |
|
""" |
|
Requires that at least one C{ParseExpression} is found. |
|
If two expressions match, the first one listed is the one that will match. |
|
May be constructed using the C{'|'} operator. |
|
|
|
Example:: |
|
# construct MatchFirst using '|' operator |
|
|
|
# watch the order of expressions to match |
|
number = Word(nums) | Combine(Word(nums) + '.' + Word(nums)) |
|
print(number.searchString("123 3.1416 789")) # Fail! -> [['123'], ['3'], ['1416'], ['789']] |
|
|
|
# put more selective expression first |
|
number = Combine(Word(nums) + '.' + Word(nums)) | Word(nums) |
|
print(number.searchString("123 3.1416 789")) # Better -> [['123'], ['3.1416'], ['789']] |
|
""" |
|
def __init__( self, exprs, savelist = False ): |
|
super(MatchFirst,self).__init__(exprs, savelist) |
|
if self.exprs: |
|
self.mayReturnEmpty = any(e.mayReturnEmpty for e in self.exprs) |
|
else: |
|
self.mayReturnEmpty = True |
|
|
|
def parseImpl( self, instring, loc, doActions=True ): |
|
maxExcLoc = -1 |
|
maxException = None |
|
for e in self.exprs: |
|
try: |
|
ret = e._parse( instring, loc, doActions ) |
|
return ret |
|
except ParseException as err: |
|
if err.loc > maxExcLoc: |
|
maxException = err |
|
maxExcLoc = err.loc |
|
except IndexError: |
|
if len(instring) > maxExcLoc: |
|
maxException = ParseException(instring,len(instring),e.errmsg,self) |
|
maxExcLoc = len(instring) |
|
|
|
# only got here if no expression matched, raise exception for match that made it the furthest |
|
else: |
|
if maxException is not None: |
|
maxException.msg = self.errmsg |
|
raise maxException |
|
else: |
|
raise ParseException(instring, loc, "no defined alternatives to match", self) |
|
|
|
def __ior__(self, other ): |
|
if isinstance( other, basestring ): |
|
other = ParserElement._literalStringClass( other ) |
|
return self.append( other ) #MatchFirst( [ self, other ] ) |
|
|
|
def __str__( self ): |
|
if hasattr(self,"name"): |
|
return self.name |
|
|
|
if self.strRepr is None: |
|
self.strRepr = "{" + " | ".join(_ustr(e) for e in self.exprs) + "}" |
|
|
|
return self.strRepr |
|
|
|
def checkRecursion( self, parseElementList ): |
|
subRecCheckList = parseElementList[:] + [ self ] |
|
for e in self.exprs: |
|
e.checkRecursion( subRecCheckList ) |
|
|
|
|
|
class Each(ParseExpression): |
|
""" |
|
Requires all given C{ParseExpression}s to be found, but in any order. |
|
Expressions may be separated by whitespace. |
|
May be constructed using the C{'&'} operator. |
|
|
|
Example:: |
|
color = oneOf("RED ORANGE YELLOW GREEN BLUE PURPLE BLACK WHITE BROWN") |
|
shape_type = oneOf("SQUARE CIRCLE TRIANGLE STAR HEXAGON OCTAGON") |
|
integer = Word(nums) |
|
shape_attr = "shape:" + shape_type("shape") |
|
posn_attr = "posn:" + Group(integer("x") + ',' + integer("y"))("posn") |
|
color_attr = "color:" + color("color") |
|
size_attr = "size:" + integer("size") |
|
|
|
# use Each (using operator '&') to accept attributes in any order |
|
# (shape and posn are required, color and size are optional) |
|
shape_spec = shape_attr & posn_attr & Optional(color_attr) & Optional(size_attr) |
|
|
|
shape_spec.runTests(''' |
|
shape: SQUARE color: BLACK posn: 100, 120 |
|
shape: CIRCLE size: 50 color: BLUE posn: 50,80 |
|
color:GREEN size:20 shape:TRIANGLE posn:20,40 |
|
''' |
|
) |
|
prints:: |
|
shape: SQUARE color: BLACK posn: 100, 120 |
|
['shape:', 'SQUARE', 'color:', 'BLACK', 'posn:', ['100', ',', '120']] |
|
- color: BLACK |
|
- posn: ['100', ',', '120'] |
|
- x: 100 |
|
- y: 120 |
|
- shape: SQUARE |
|
|
|
|
|
shape: CIRCLE size: 50 color: BLUE posn: 50,80 |
|
['shape:', 'CIRCLE', 'size:', '50', 'color:', 'BLUE', 'posn:', ['50', ',', '80']] |
|
- color: BLUE |
|
- posn: ['50', ',', '80'] |
|
- x: 50 |
|
- y: 80 |
|
- shape: CIRCLE |
|
- size: 50 |
|
|
|
|
|
color: GREEN size: 20 shape: TRIANGLE posn: 20,40 |
|
['color:', 'GREEN', 'size:', '20', 'shape:', 'TRIANGLE', 'posn:', ['20', ',', '40']] |
|
- color: GREEN |
|
- posn: ['20', ',', '40'] |
|
- x: 20 |
|
- y: 40 |
|
- shape: TRIANGLE |
|
- size: 20 |
|
""" |
|
def __init__( self, exprs, savelist = True ): |
|
super(Each,self).__init__(exprs, savelist) |
|
self.mayReturnEmpty = all(e.mayReturnEmpty for e in self.exprs) |
|
self.skipWhitespace = True |
|
self.initExprGroups = True |
|
|
|
def parseImpl( self, instring, loc, doActions=True ): |
|
if self.initExprGroups: |
|
self.opt1map = dict((id(e.expr),e) for e in self.exprs if isinstance(e,Optional)) |
|
opt1 = [ e.expr for e in self.exprs if isinstance(e,Optional) ] |
|
opt2 = [ e for e in self.exprs if e.mayReturnEmpty and not isinstance(e,Optional)] |
|
self.optionals = opt1 + opt2 |
|
self.multioptionals = [ e.expr for e in self.exprs if isinstance(e,ZeroOrMore) ] |
|
self.multirequired = [ e.expr for e in self.exprs if isinstance(e,OneOrMore) ] |
|
self.required = [ e for e in self.exprs if not isinstance(e,(Optional,ZeroOrMore,OneOrMore)) ] |
|
self.required += self.multirequired |
|
self.initExprGroups = False |
|
tmpLoc = loc |
|
tmpReqd = self.required[:] |
|
tmpOpt = self.optionals[:] |
|
matchOrder = [] |
|
|
|
keepMatching = True |
|
while keepMatching: |
|
tmpExprs = tmpReqd + tmpOpt + self.multioptionals + self.multirequired |
|
failed = [] |
|
for e in tmpExprs: |
|
try: |
|
tmpLoc = e.tryParse( instring, tmpLoc ) |
|
except ParseException: |
|
failed.append(e) |
|
else: |
|
matchOrder.append(self.opt1map.get(id(e),e)) |
|
if e in tmpReqd: |
|
tmpReqd.remove(e) |
|
elif e in tmpOpt: |
|
tmpOpt.remove(e) |
|
if len(failed) == len(tmpExprs): |
|
keepMatching = False |
|
|
|
if tmpReqd: |
|
missing = ", ".join(_ustr(e) for e in tmpReqd) |
|
raise ParseException(instring,loc,"Missing one or more required elements (%s)" % missing ) |
|
|
|
# add any unmatched Optionals, in case they have default values defined |
|
matchOrder += [e for e in self.exprs if isinstance(e,Optional) and e.expr in tmpOpt] |
|
|
|
resultlist = [] |
|
for e in matchOrder: |
|
loc,results = e._parse(instring,loc,doActions) |
|
resultlist.append(results) |
|
|
|
finalResults = sum(resultlist, ParseResults([])) |
|
return loc, finalResults |
|
|
|
def __str__( self ): |
|
if hasattr(self,"name"): |
|
return self.name |
|
|
|
if self.strRepr is None: |
|
self.strRepr = "{" + " & ".join(_ustr(e) for e in self.exprs) + "}" |
|
|
|
return self.strRepr |
|
|
|
def checkRecursion( self, parseElementList ): |
|
subRecCheckList = parseElementList[:] + [ self ] |
|
for e in self.exprs: |
|
e.checkRecursion( subRecCheckList ) |
|
|
|
|
|
class ParseElementEnhance(ParserElement): |
|
""" |
|
Abstract subclass of C{ParserElement}, for combining and post-processing parsed tokens. |
|
""" |
|
def __init__( self, expr, savelist=False ): |
|
super(ParseElementEnhance,self).__init__(savelist) |
|
if isinstance( expr, basestring ): |
|
if issubclass(ParserElement._literalStringClass, Token): |
|
expr = ParserElement._literalStringClass(expr) |
|
else: |
|
expr = ParserElement._literalStringClass(Literal(expr)) |
|
self.expr = expr |
|
self.strRepr = None |
|
if expr is not None: |
|
self.mayIndexError = expr.mayIndexError |
|
self.mayReturnEmpty = expr.mayReturnEmpty |
|
self.setWhitespaceChars( expr.whiteChars ) |
|
self.skipWhitespace = expr.skipWhitespace |
|
self.saveAsList = expr.saveAsList |
|
self.callPreparse = expr.callPreparse |
|
self.ignoreExprs.extend(expr.ignoreExprs) |
|
|
|
def parseImpl( self, instring, loc, doActions=True ): |
|
if self.expr is not None: |
|
return self.expr._parse( instring, loc, doActions, callPreParse=False ) |
|
else: |
|
raise ParseException("",loc,self.errmsg,self) |
|
|
|
def leaveWhitespace( self ): |
|
self.skipWhitespace = False |
|
self.expr = self.expr.copy() |
|
if self.expr is not None: |
|
self.expr.leaveWhitespace() |
|
return self |
|
|
|
def ignore( self, other ): |
|
if isinstance( other, Suppress ): |
|
if other not in self.ignoreExprs: |
|
super( ParseElementEnhance, self).ignore( other ) |
|
if self.expr is not None: |
|
self.expr.ignore( self.ignoreExprs[-1] ) |
|
else: |
|
super( ParseElementEnhance, self).ignore( other ) |
|
if self.expr is not None: |
|
self.expr.ignore( self.ignoreExprs[-1] ) |
|
return self |
|
|
|
def streamline( self ): |
|
super(ParseElementEnhance,self).streamline() |
|
if self.expr is not None: |
|
self.expr.streamline() |
|
return self |
|
|
|
def checkRecursion( self, parseElementList ): |
|
if self in parseElementList: |
|
raise RecursiveGrammarException( parseElementList+[self] ) |
|
subRecCheckList = parseElementList[:] + [ self ] |
|
if self.expr is not None: |
|
self.expr.checkRecursion( subRecCheckList ) |
|
|
|
def validate( self, validateTrace=[] ): |
|
tmp = validateTrace[:]+[self] |
|
if self.expr is not None: |
|
self.expr.validate(tmp) |
|
self.checkRecursion( [] ) |
|
|
|
def __str__( self ): |
|
try: |
|
return super(ParseElementEnhance,self).__str__() |
|
except Exception: |
|
pass |
|
|
|
if self.strRepr is None and self.expr is not None: |
|
self.strRepr = "%s:(%s)" % ( self.__class__.__name__, _ustr(self.expr) ) |
|
return self.strRepr |
|
|
|
|
|
class FollowedBy(ParseElementEnhance): |
|
""" |
|
Lookahead matching of the given parse expression. C{FollowedBy} |
|
does I{not} advance the parsing position within the input string, it only |
|
verifies that the specified parse expression matches at the current |
|
position. C{FollowedBy} always returns a null token list. |
|
|
|
Example:: |
|
# use FollowedBy to match a label only if it is followed by a ':' |
|
data_word = Word(alphas) |
|
label = data_word + FollowedBy(':') |
|
attr_expr = Group(label + Suppress(':') + OneOrMore(data_word, stopOn=label).setParseAction(' '.join)) |
|
|
|
OneOrMore(attr_expr).parseString("shape: SQUARE color: BLACK posn: upper left").pprint() |
|
prints:: |
|
[['shape', 'SQUARE'], ['color', 'BLACK'], ['posn', 'upper left']] |
|
""" |
|
def __init__( self, expr ): |
|
super(FollowedBy,self).__init__(expr) |
|
self.mayReturnEmpty = True |
|
|
|
def parseImpl( self, instring, loc, doActions=True ): |
|
self.expr.tryParse( instring, loc ) |
|
return loc, [] |
|
|
|
|
|
class NotAny(ParseElementEnhance): |
|
""" |
|
Lookahead to disallow matching with the given parse expression. C{NotAny} |
|
does I{not} advance the parsing position within the input string, it only |
|
verifies that the specified parse expression does I{not} match at the current |
|
position. Also, C{NotAny} does I{not} skip over leading whitespace. C{NotAny} |
|
always returns a null token list. May be constructed using the '~' operator. |
|
|
|
Example:: |
|
|
|
""" |
|
def __init__( self, expr ): |
|
super(NotAny,self).__init__(expr) |
|
#~ self.leaveWhitespace() |
|
self.skipWhitespace = False # do NOT use self.leaveWhitespace(), don't want to propagate to exprs |
|
self.mayReturnEmpty = True |
|
self.errmsg = "Found unwanted token, "+_ustr(self.expr) |
|
|
|
def parseImpl( self, instring, loc, doActions=True ): |
|
if self.expr.canParseNext(instring, loc): |
|
raise ParseException(instring, loc, self.errmsg, self) |
|
return loc, [] |
|
|
|
def __str__( self ): |
|
if hasattr(self,"name"): |
|
return self.name |
|
|
|
if self.strRepr is None: |
|
self.strRepr = "~{" + _ustr(self.expr) + "}" |
|
|
|
return self.strRepr |
|
|
|
class _MultipleMatch(ParseElementEnhance): |
|
def __init__( self, expr, stopOn=None): |
|
super(_MultipleMatch, self).__init__(expr) |
|
self.saveAsList = True |
|
ender = stopOn |
|
if isinstance(ender, basestring): |
|
ender = ParserElement._literalStringClass(ender) |
|
self.not_ender = ~ender if ender is not None else None |
|
|
|
def parseImpl( self, instring, loc, doActions=True ): |
|
self_expr_parse = self.expr._parse |
|
self_skip_ignorables = self._skipIgnorables |
|
check_ender = self.not_ender is not None |
|
if check_ender: |
|
try_not_ender = self.not_ender.tryParse |
|
|
|
# must be at least one (but first see if we are the stopOn sentinel; |
|
# if so, fail) |
|
if check_ender: |
|
try_not_ender(instring, loc) |
|
loc, tokens = self_expr_parse( instring, loc, doActions, callPreParse=False ) |
|
try: |
|
hasIgnoreExprs = (not not self.ignoreExprs) |
|
while 1: |
|
if check_ender: |
|
try_not_ender(instring, loc) |
|
if hasIgnoreExprs: |
|
preloc = self_skip_ignorables( instring, loc ) |
|
else: |
|
preloc = loc |
|
loc, tmptokens = self_expr_parse( instring, preloc, doActions ) |
|
if tmptokens or tmptokens.haskeys(): |
|
tokens += tmptokens |
|
except (ParseException,IndexError): |
|
pass |
|
|
|
return loc, tokens |
|
|
|
class OneOrMore(_MultipleMatch): |
|
""" |
|
Repetition of one or more of the given expression. |
|
|
|
Parameters: |
|
- expr - expression that must match one or more times |
|
- stopOn - (default=C{None}) - expression for a terminating sentinel |
|
(only required if the sentinel would ordinarily match the repetition |
|
expression) |
|
|
|
Example:: |
|
data_word = Word(alphas) |
|
label = data_word + FollowedBy(':') |
|
attr_expr = Group(label + Suppress(':') + OneOrMore(data_word).setParseAction(' '.join)) |
|
|
|
text = "shape: SQUARE posn: upper left color: BLACK" |
|
OneOrMore(attr_expr).parseString(text).pprint() # Fail! read 'color' as data instead of next label -> [['shape', 'SQUARE color']] |
|
|
|
# use stopOn attribute for OneOrMore to avoid reading label string as part of the data |
|
attr_expr = Group(label + Suppress(':') + OneOrMore(data_word, stopOn=label).setParseAction(' '.join)) |
|
OneOrMore(attr_expr).parseString(text).pprint() # Better -> [['shape', 'SQUARE'], ['posn', 'upper left'], ['color', 'BLACK']] |
|
|
|
# could also be written as |
|
(attr_expr * (1,)).parseString(text).pprint() |
|
""" |
|
|
|
def __str__( self ): |
|
if hasattr(self,"name"): |
|
return self.name |
|
|
|
if self.strRepr is None: |
|
self.strRepr = "{" + _ustr(self.expr) + "}..." |
|
|
|
return self.strRepr |
|
|
|
class ZeroOrMore(_MultipleMatch): |
|
""" |
|
Optional repetition of zero or more of the given expression. |
|
|
|
Parameters: |
|
- expr - expression that must match zero or more times |
|
- stopOn - (default=C{None}) - expression for a terminating sentinel |
|
(only required if the sentinel would ordinarily match the repetition |
|
expression) |
|
|
|
Example: similar to L{OneOrMore} |
|
""" |
|
def __init__( self, expr, stopOn=None): |
|
super(ZeroOrMore,self).__init__(expr, stopOn=stopOn) |
|
self.mayReturnEmpty = True |
|
|
|
def parseImpl( self, instring, loc, doActions=True ): |
|
try: |
|
return super(ZeroOrMore, self).parseImpl(instring, loc, doActions) |
|
except (ParseException,IndexError): |
|
return loc, [] |
|
|
|
def __str__( self ): |
|
if hasattr(self,"name"): |
|
return self.name |
|
|
|
if self.strRepr is None: |
|
self.strRepr = "[" + _ustr(self.expr) + "]..." |
|
|
|
return self.strRepr |
|
|
|
class _NullToken(object): |
|
def __bool__(self): |
|
return False |
|
__nonzero__ = __bool__ |
|
def __str__(self): |
|
return "" |
|
|
|
_optionalNotMatched = _NullToken() |
|
class Optional(ParseElementEnhance): |
|
""" |
|
Optional matching of the given expression. |
|
|
|
Parameters: |
|
- expr - expression that must match zero or more times |
|
- default (optional) - value to be returned if the optional expression is not found. |
|
|
|
Example:: |
|
# US postal code can be a 5-digit zip, plus optional 4-digit qualifier |
|
zip = Combine(Word(nums, exact=5) + Optional('-' + Word(nums, exact=4))) |
|
zip.runTests(''' |
|
# traditional ZIP code |
|
12345 |
|
|
|
# ZIP+4 form |
|
12101-0001 |
|
|
|
# invalid ZIP |
|
98765- |
|
''') |
|
prints:: |
|
# traditional ZIP code |
|
12345 |
|
['12345'] |
|
|
|
# ZIP+4 form |
|
12101-0001 |
|
['12101-0001'] |
|
|
|
# invalid ZIP |
|
98765- |
|
^ |
|
FAIL: Expected end of text (at char 5), (line:1, col:6) |
|
""" |
|
def __init__( self, expr, default=_optionalNotMatched ): |
|
super(Optional,self).__init__( expr, savelist=False ) |
|
self.saveAsList = self.expr.saveAsList |
|
self.defaultValue = default |
|
self.mayReturnEmpty = True |
|
|
|
def parseImpl( self, instring, loc, doActions=True ): |
|
try: |
|
loc, tokens = self.expr._parse( instring, loc, doActions, callPreParse=False ) |
|
except (ParseException,IndexError): |
|
if self.defaultValue is not _optionalNotMatched: |
|
if self.expr.resultsName: |
|
tokens = ParseResults([ self.defaultValue ]) |
|
tokens[self.expr.resultsName] = self.defaultValue |
|
else: |
|
tokens = [ self.defaultValue ] |
|
else: |
|
tokens = [] |
|
return loc, tokens |
|
|
|
def __str__( self ): |
|
if hasattr(self,"name"): |
|
return self.name |
|
|
|
if self.strRepr is None: |
|
self.strRepr = "[" + _ustr(self.expr) + "]" |
|
|
|
return self.strRepr |
|
|
|
class SkipTo(ParseElementEnhance): |
|
""" |
|
Token for skipping over all undefined text until the matched expression is found. |
|
|
|
Parameters: |
|
- expr - target expression marking the end of the data to be skipped |
|
- include - (default=C{False}) if True, the target expression is also parsed |
|
(the skipped text and target expression are returned as a 2-element list). |
|
- ignore - (default=C{None}) used to define grammars (typically quoted strings and |
|
comments) that might contain false matches to the target expression |
|
- failOn - (default=C{None}) define expressions that are not allowed to be |
|
included in the skipped test; if found before the target expression is found, |
|
the SkipTo is not a match |
|
|
|
Example:: |
|
report = ''' |
|
Outstanding Issues Report - 1 Jan 2000 |
|
|
|
# | Severity | Description | Days Open |
|
-----+----------+-------------------------------------------+----------- |
|
101 | Critical | Intermittent system crash | 6 |
|
94 | Cosmetic | Spelling error on Login ('log|n') | 14 |
|
79 | Minor | System slow when running too many reports | 47 |
|
''' |
|
integer = Word(nums) |
|
SEP = Suppress('|') |
|
# use SkipTo to simply match everything up until the next SEP |
|
# - ignore quoted strings, so that a '|' character inside a quoted string does not match |
|
# - parse action will call token.strip() for each matched token, i.e., the description body |
|
string_data = SkipTo(SEP, ignore=quotedString) |
|
string_data.setParseAction(tokenMap(str.strip)) |
|
ticket_expr = (integer("issue_num") + SEP |
|
+ string_data("sev") + SEP |
|
+ string_data("desc") + SEP |
|
+ integer("days_open")) |
|
|
|
for tkt in ticket_expr.searchString(report): |
|
print tkt.dump() |
|
prints:: |
|
['101', 'Critical', 'Intermittent system crash', '6'] |
|
- days_open: 6 |
|
- desc: Intermittent system crash |
|
- issue_num: 101 |
|
- sev: Critical |
|
['94', 'Cosmetic', "Spelling error on Login ('log|n')", '14'] |
|
- days_open: 14 |
|
- desc: Spelling error on Login ('log|n') |
|
- issue_num: 94 |
|
- sev: Cosmetic |
|
['79', 'Minor', 'System slow when running too many reports', '47'] |
|
- days_open: 47 |
|
- desc: System slow when running too many reports |
|
- issue_num: 79 |
|
- sev: Minor |
|
""" |
|
def __init__( self, other, include=False, ignore=None, failOn=None ): |
|
super( SkipTo, self ).__init__( other ) |
|
self.ignoreExpr = ignore |
|
self.mayReturnEmpty = True |
|
self.mayIndexError = False |
|
self.includeMatch = include |
|
self.asList = False |
|
if isinstance(failOn, basestring): |
|
self.failOn = ParserElement._literalStringClass(failOn) |
|
else: |
|
self.failOn = failOn |
|
self.errmsg = "No match found for "+_ustr(self.expr) |
|
|
|
def parseImpl( self, instring, loc, doActions=True ): |
|
startloc = loc |
|
instrlen = len(instring) |
|
expr = self.expr |
|
expr_parse = self.expr._parse |
|
self_failOn_canParseNext = self.failOn.canParseNext if self.failOn is not None else None |
|
self_ignoreExpr_tryParse = self.ignoreExpr.tryParse if self.ignoreExpr is not None else None |
|
|
|
tmploc = loc |
|
while tmploc <= instrlen: |
|
if self_failOn_canParseNext is not None: |
|
# break if failOn expression matches |
|
if self_failOn_canParseNext(instring, tmploc): |
|
break |
|
|
|
if self_ignoreExpr_tryParse is not None: |
|
# advance past ignore expressions |
|
while 1: |
|
try: |
|
tmploc = self_ignoreExpr_tryParse(instring, tmploc) |
|
except ParseBaseException: |
|
break |
|
|
|
try: |
|
expr_parse(instring, tmploc, doActions=False, callPreParse=False) |
|
except (ParseException, IndexError): |
|
# no match, advance loc in string |
|
tmploc += 1 |
|
else: |
|
# matched skipto expr, done |
|
break |
|
|
|
else: |
|
# ran off the end of the input string without matching skipto expr, fail |
|
raise ParseException(instring, loc, self.errmsg, self) |
|
|
|
# build up return values |
|
loc = tmploc |
|
skiptext = instring[startloc:loc] |
|
skipresult = ParseResults(skiptext) |
|
|
|
if self.includeMatch: |
|
loc, mat = expr_parse(instring,loc,doActions,callPreParse=False) |
|
skipresult += mat |
|
|
|
return loc, skipresult |
|
|
|
class Forward(ParseElementEnhance): |
|
""" |
|
Forward declaration of an expression to be defined later - |
|
used for recursive grammars, such as algebraic infix notation. |
|
When the expression is known, it is assigned to the C{Forward} variable using the '<<' operator. |
|
|
|
Note: take care when assigning to C{Forward} not to overlook precedence of operators. |
|
Specifically, '|' has a lower precedence than '<<', so that:: |
|
fwdExpr << a | b | c |
|
will actually be evaluated as:: |
|
(fwdExpr << a) | b | c |
|
thereby leaving b and c out as parseable alternatives. It is recommended that you |
|
explicitly group the values inserted into the C{Forward}:: |
|
fwdExpr << (a | b | c) |
|
Converting to use the '<<=' operator instead will avoid this problem. |
|
|
|
See L{ParseResults.pprint} for an example of a recursive parser created using |
|
C{Forward}. |
|
""" |
|
def __init__( self, other=None ): |
|
super(Forward,self).__init__( other, savelist=False ) |
|
|
|
def __lshift__( self, other ): |
|
if isinstance( other, basestring ): |
|
other = ParserElement._literalStringClass(other) |
|
self.expr = other |
|
self.strRepr = None |
|
self.mayIndexError = self.expr.mayIndexError |
|
self.mayReturnEmpty = self.expr.mayReturnEmpty |
|
self.setWhitespaceChars( self.expr.whiteChars ) |
|
self.skipWhitespace = self.expr.skipWhitespace |
|
self.saveAsList = self.expr.saveAsList |
|
self.ignoreExprs.extend(self.expr.ignoreExprs) |
|
return self |
|
|
|
def __ilshift__(self, other): |
|
return self << other |
|
|
|
def leaveWhitespace( self ): |
|
self.skipWhitespace = False |
|
return self |
|
|
|
def streamline( self ): |
|
if not self.streamlined: |
|
self.streamlined = True |
|
if self.expr is not None: |
|
self.expr.streamline() |
|
return self |
|
|
|
def validate( self, validateTrace=[] ): |
|
if self not in validateTrace: |
|
tmp = validateTrace[:]+[self] |
|
if self.expr is not None: |
|
self.expr.validate(tmp) |
|
self.checkRecursion([]) |
|
|
|
def __str__( self ): |
|
if hasattr(self,"name"): |
|
return self.name |
|
return self.__class__.__name__ + ": ..." |
|
|
|
# stubbed out for now - creates awful memory and perf issues |
|
self._revertClass = self.__class__ |
|
self.__class__ = _ForwardNoRecurse |
|
try: |
|
if self.expr is not None: |
|
retString = _ustr(self.expr) |
|
else: |
|
retString = "None" |
|
finally: |
|
self.__class__ = self._revertClass |
|
return self.__class__.__name__ + ": " + retString |
|
|
|
def copy(self): |
|
if self.expr is not None: |
|
return super(Forward,self).copy() |
|
else: |
|
ret = Forward() |
|
ret <<= self |
|
return ret |
|
|
|
class _ForwardNoRecurse(Forward): |
|
def __str__( self ): |
|
return "..." |
|
|
|
class TokenConverter(ParseElementEnhance): |
|
""" |
|
Abstract subclass of C{ParseExpression}, for converting parsed results. |
|
""" |
|
def __init__( self, expr, savelist=False ): |
|
super(TokenConverter,self).__init__( expr )#, savelist ) |
|
self.saveAsList = False |
|
|
|
class Combine(TokenConverter): |
|
""" |
|
Converter to concatenate all matching tokens to a single string. |
|
By default, the matching patterns must also be contiguous in the input string; |
|
this can be disabled by specifying C{'adjacent=False'} in the constructor. |
|
|
|
Example:: |
|
real = Word(nums) + '.' + Word(nums) |
|
print(real.parseString('3.1416')) # -> ['3', '.', '1416'] |
|
# will also erroneously match the following |
|
print(real.parseString('3. 1416')) # -> ['3', '.', '1416'] |
|
|
|
real = Combine(Word(nums) + '.' + Word(nums)) |
|
print(real.parseString('3.1416')) # -> ['3.1416'] |
|
# no match when there are internal spaces |
|
print(real.parseString('3. 1416')) # -> Exception: Expected W:(0123...) |
|
""" |
|
def __init__( self, expr, joinString="", adjacent=True ): |
|
super(Combine,self).__init__( expr ) |
|
# suppress whitespace-stripping in contained parse expressions, but re-enable it on the Combine itself |
|
if adjacent: |
|
self.leaveWhitespace() |
|
self.adjacent = adjacent |
|
self.skipWhitespace = True |
|
self.joinString = joinString |
|
self.callPreparse = True |
|
|
|
def ignore( self, other ): |
|
if self.adjacent: |
|
ParserElement.ignore(self, other) |
|
else: |
|
super( Combine, self).ignore( other ) |
|
return self |
|
|
|
def postParse( self, instring, loc, tokenlist ): |
|
retToks = tokenlist.copy() |
|
del retToks[:] |
|
retToks += ParseResults([ "".join(tokenlist._asStringList(self.joinString)) ], modal=self.modalResults) |
|
|
|
if self.resultsName and retToks.haskeys(): |
|
return [ retToks ] |
|
else: |
|
return retToks |
|
|
|
class Group(TokenConverter): |
|
""" |
|
Converter to return the matched tokens as a list - useful for returning tokens of C{L{ZeroOrMore}} and C{L{OneOrMore}} expressions. |
|
|
|
Example:: |
|
ident = Word(alphas) |
|
num = Word(nums) |
|
term = ident | num |
|
func = ident + Optional(delimitedList(term)) |
|
print(func.parseString("fn a,b,100")) # -> ['fn', 'a', 'b', '100'] |
|
|
|
func = ident + Group(Optional(delimitedList(term))) |
|
print(func.parseString("fn a,b,100")) # -> ['fn', ['a', 'b', '100']] |
|
""" |
|
def __init__( self, expr ): |
|
super(Group,self).__init__( expr ) |
|
self.saveAsList = True |
|
|
|
def postParse( self, instring, loc, tokenlist ): |
|
return [ tokenlist ] |
|
|
|
class Dict(TokenConverter): |
|
""" |
|
Converter to return a repetitive expression as a list, but also as a dictionary. |
|
Each element can also be referenced using the first token in the expression as its key. |
|
Useful for tabular report scraping when the first column can be used as a item key. |
|
|
|
Example:: |
|
data_word = Word(alphas) |
|
label = data_word + FollowedBy(':') |
|
attr_expr = Group(label + Suppress(':') + OneOrMore(data_word).setParseAction(' '.join)) |
|
|
|
text = "shape: SQUARE posn: upper left color: light blue texture: burlap" |
|
attr_expr = (label + Suppress(':') + OneOrMore(data_word, stopOn=label).setParseAction(' '.join)) |
|
|
|
# print attributes as plain groups |
|
print(OneOrMore(attr_expr).parseString(text).dump()) |
|
|
|
# instead of OneOrMore(expr), parse using Dict(OneOrMore(Group(expr))) - Dict will auto-assign names |
|
result = Dict(OneOrMore(Group(attr_expr))).parseString(text) |
|
print(result.dump()) |
|
|
|
# access named fields as dict entries, or output as dict |
|
print(result['shape']) |
|
print(result.asDict()) |
|
prints:: |
|
['shape', 'SQUARE', 'posn', 'upper left', 'color', 'light blue', 'texture', 'burlap'] |
|
|
|
[['shape', 'SQUARE'], ['posn', 'upper left'], ['color', 'light blue'], ['texture', 'burlap']] |
|
- color: light blue |
|
- posn: upper left |
|
- shape: SQUARE |
|
- texture: burlap |
|
SQUARE |
|
{'color': 'light blue', 'posn': 'upper left', 'texture': 'burlap', 'shape': 'SQUARE'} |
|
See more examples at L{ParseResults} of accessing fields by results name. |
|
""" |
|
def __init__( self, expr ): |
|
super(Dict,self).__init__( expr ) |
|
self.saveAsList = True |
|
|
|
def postParse( self, instring, loc, tokenlist ): |
|
for i,tok in enumerate(tokenlist): |
|
if len(tok) == 0: |
|
continue |
|
ikey = tok[0] |
|
if isinstance(ikey,int): |
|
ikey = _ustr(tok[0]).strip() |
|
if len(tok)==1: |
|
tokenlist[ikey] = _ParseResultsWithOffset("",i) |
|
elif len(tok)==2 and not isinstance(tok[1],ParseResults): |
|
tokenlist[ikey] = _ParseResultsWithOffset(tok[1],i) |
|
else: |
|
dictvalue = tok.copy() #ParseResults(i) |
|
del dictvalue[0] |
|
if len(dictvalue)!= 1 or (isinstance(dictvalue,ParseResults) and dictvalue.haskeys()): |
|
tokenlist[ikey] = _ParseResultsWithOffset(dictvalue,i) |
|
else: |
|
tokenlist[ikey] = _ParseResultsWithOffset(dictvalue[0],i) |
|
|
|
if self.resultsName: |
|
return [ tokenlist ] |
|
else: |
|
return tokenlist |
|
|
|
|
|
class Suppress(TokenConverter): |
|
""" |
|
Converter for ignoring the results of a parsed expression. |
|
|
|
Example:: |
|
source = "a, b, c,d" |
|
wd = Word(alphas) |
|
wd_list1 = wd + ZeroOrMore(',' + wd) |
|
print(wd_list1.parseString(source)) |
|
|
|
# often, delimiters that are useful during parsing are just in the |
|
# way afterward - use Suppress to keep them out of the parsed output |
|
wd_list2 = wd + ZeroOrMore(Suppress(',') + wd) |
|
print(wd_list2.parseString(source)) |
|
prints:: |
|
['a', ',', 'b', ',', 'c', ',', 'd'] |
|
['a', 'b', 'c', 'd'] |
|
(See also L{delimitedList}.) |
|
""" |
|
def postParse( self, instring, loc, tokenlist ): |
|
return [] |
|
|
|
def suppress( self ): |
|
return self |
|
|
|
|
|
class OnlyOnce(object): |
|
""" |
|
Wrapper for parse actions, to ensure they are only called once. |
|
""" |
|
def __init__(self, methodCall): |
|
self.callable = _trim_arity(methodCall) |
|
self.called = False |
|
def __call__(self,s,l,t): |
|
if not self.called: |
|
results = self.callable(s,l,t) |
|
self.called = True |
|
return results |
|
raise ParseException(s,l,"") |
|
def reset(self): |
|
self.called = False |
|
|
|
def traceParseAction(f): |
|
""" |
|
Decorator for debugging parse actions. |
|
|
|
When the parse action is called, this decorator will print C{">> entering I{method-name}(line:I{current_source_line}, I{parse_location}, I{matched_tokens})".} |
|
When the parse action completes, the decorator will print C{"<<"} followed by the returned value, or any exception that the parse action raised. |
|
|
|
Example:: |
|
wd = Word(alphas) |
|
|
|
@traceParseAction |
|
def remove_duplicate_chars(tokens): |
|
return ''.join(sorted(set(''.join(tokens)))) |
|
|
|
wds = OneOrMore(wd).setParseAction(remove_duplicate_chars) |
|
print(wds.parseString("slkdjs sld sldd sdlf sdljf")) |
|
prints:: |
|
>>entering remove_duplicate_chars(line: 'slkdjs sld sldd sdlf sdljf', 0, (['slkdjs', 'sld', 'sldd', 'sdlf', 'sdljf'], {})) |
|
<<leaving remove_duplicate_chars (ret: 'dfjkls') |
|
['dfjkls'] |
|
""" |
|
f = _trim_arity(f) |
|
def z(*paArgs): |
|
thisFunc = f.__name__ |
|
s,l,t = paArgs[-3:] |
|
if len(paArgs)>3: |
|
thisFunc = paArgs[0].__class__.__name__ + '.' + thisFunc |
|
sys.stderr.write( ">>entering %s(line: '%s', %d, %r)\n" % (thisFunc,line(l,s),l,t) ) |
|
try: |
|
ret = f(*paArgs) |
|
except Exception as exc: |
|
sys.stderr.write( "<<leaving %s (exception: %s)\n" % (thisFunc,exc) ) |
|
raise |
|
sys.stderr.write( "<<leaving %s (ret: %r)\n" % (thisFunc,ret) ) |
|
return ret |
|
try: |
|
z.__name__ = f.__name__ |
|
except AttributeError: |
|
pass |
|
return z |
|
|
|
# |
|
# global helpers |
|
# |
|
def delimitedList( expr, delim=",", combine=False ): |
|
""" |
|
Helper to define a delimited list of expressions - the delimiter defaults to ','. |
|
By default, the list elements and delimiters can have intervening whitespace, and |
|
comments, but this can be overridden by passing C{combine=True} in the constructor. |
|
If C{combine} is set to C{True}, the matching tokens are returned as a single token |
|
string, with the delimiters included; otherwise, the matching tokens are returned |
|
as a list of tokens, with the delimiters suppressed. |
|
|
|
Example:: |
|
delimitedList(Word(alphas)).parseString("aa,bb,cc") # -> ['aa', 'bb', 'cc'] |
|
delimitedList(Word(hexnums), delim=':', combine=True).parseString("AA:BB:CC:DD:EE") # -> ['AA:BB:CC:DD:EE'] |
|
""" |
|
dlName = _ustr(expr)+" ["+_ustr(delim)+" "+_ustr(expr)+"]..." |
|
if combine: |
|
return Combine( expr + ZeroOrMore( delim + expr ) ).setName(dlName) |
|
else: |
|
return ( expr + ZeroOrMore( Suppress( delim ) + expr ) ).setName(dlName) |
|
|
|
def countedArray( expr, intExpr=None ): |
|
""" |
|
Helper to define a counted list of expressions. |
|
This helper defines a pattern of the form:: |
|
integer expr expr expr... |
|
where the leading integer tells how many expr expressions follow. |
|
The matched tokens returns the array of expr tokens as a list - the leading count token is suppressed. |
|
|
|
If C{intExpr} is specified, it should be a pyparsing expression that produces an integer value. |
|
|
|
Example:: |
|
countedArray(Word(alphas)).parseString('2 ab cd ef') # -> ['ab', 'cd'] |
|
|
|
# in this parser, the leading integer value is given in binary, |
|
# '10' indicating that 2 values are in the array |
|
binaryConstant = Word('01').setParseAction(lambda t: int(t[0], 2)) |
|
countedArray(Word(alphas), intExpr=binaryConstant).parseString('10 ab cd ef') # -> ['ab', 'cd'] |
|
""" |
|
arrayExpr = Forward() |
|
def countFieldParseAction(s,l,t): |
|
n = t[0] |
|
arrayExpr << (n and Group(And([expr]*n)) or Group(empty)) |
|
return [] |
|
if intExpr is None: |
|
intExpr = Word(nums).setParseAction(lambda t:int(t[0])) |
|
else: |
|
intExpr = intExpr.copy() |
|
intExpr.setName("arrayLen") |
|
intExpr.addParseAction(countFieldParseAction, callDuringTry=True) |
|
return ( intExpr + arrayExpr ).setName('(len) ' + _ustr(expr) + '...') |
|
|
|
def _flatten(L): |
|
ret = [] |
|
for i in L: |
|
if isinstance(i,list): |
|
ret.extend(_flatten(i)) |
|
else: |
|
ret.append(i) |
|
return ret |
|
|
|
def matchPreviousLiteral(expr): |
|
""" |
|
Helper to define an expression that is indirectly defined from |
|
the tokens matched in a previous expression, that is, it looks |
|
for a 'repeat' of a previous expression. For example:: |
|
first = Word(nums) |
|
second = matchPreviousLiteral(first) |
|
matchExpr = first + ":" + second |
|
will match C{"1:1"}, but not C{"1:2"}. Because this matches a |
|
previous literal, will also match the leading C{"1:1"} in C{"1:10"}. |
|
If this is not desired, use C{matchPreviousExpr}. |
|
Do I{not} use with packrat parsing enabled. |
|
""" |
|
rep = Forward() |
|
def copyTokenToRepeater(s,l,t): |
|
if t: |
|
if len(t) == 1: |
|
rep << t[0] |
|
else: |
|
# flatten t tokens |
|
tflat = _flatten(t.asList()) |
|
rep << And(Literal(tt) for tt in tflat) |
|
else: |
|
rep << Empty() |
|
expr.addParseAction(copyTokenToRepeater, callDuringTry=True) |
|
rep.setName('(prev) ' + _ustr(expr)) |
|
return rep |
|
|
|
def matchPreviousExpr(expr): |
|
""" |
|
Helper to define an expression that is indirectly defined from |
|
the tokens matched in a previous expression, that is, it looks |
|
for a 'repeat' of a previous expression. For example:: |
|
first = Word(nums) |
|
second = matchPreviousExpr(first) |
|
matchExpr = first + ":" + second |
|
will match C{"1:1"}, but not C{"1:2"}. Because this matches by |
|
expressions, will I{not} match the leading C{"1:1"} in C{"1:10"}; |
|
the expressions are evaluated first, and then compared, so |
|
C{"1"} is compared with C{"10"}. |
|
Do I{not} use with packrat parsing enabled. |
|
""" |
|
rep = Forward() |
|
e2 = expr.copy() |
|
rep <<= e2 |
|
def copyTokenToRepeater(s,l,t): |
|
matchTokens = _flatten(t.asList()) |
|
def mustMatchTheseTokens(s,l,t): |
|
theseTokens = _flatten(t.asList()) |
|
if theseTokens != matchTokens: |
|
raise ParseException("",0,"") |
|
rep.setParseAction( mustMatchTheseTokens, callDuringTry=True ) |
|
expr.addParseAction(copyTokenToRepeater, callDuringTry=True) |
|
rep.setName('(prev) ' + _ustr(expr)) |
|
return rep |
|
|
|
def _escapeRegexRangeChars(s): |
|
#~ escape these chars: ^-] |
|
for c in r"\^-]": |
|
s = s.replace(c,_bslash+c) |
|
s = s.replace("\n",r"\n") |
|
s = s.replace("\t",r"\t") |
|
return _ustr(s) |
|
|
|
def oneOf( strs, caseless=False, useRegex=True ): |
|
""" |
|
Helper to quickly define a set of alternative Literals, and makes sure to do |
|
longest-first testing when there is a conflict, regardless of the input order, |
|
but returns a C{L{MatchFirst}} for best performance. |
|
|
|
Parameters: |
|
- strs - a string of space-delimited literals, or a collection of string literals |
|
- caseless - (default=C{False}) - treat all literals as caseless |
|
- useRegex - (default=C{True}) - as an optimization, will generate a Regex |
|
object; otherwise, will generate a C{MatchFirst} object (if C{caseless=True}, or |
|
if creating a C{Regex} raises an exception) |
|
|
|
Example:: |
|
comp_oper = oneOf("< = > <= >= !=") |
|
var = Word(alphas) |
|
number = Word(nums) |
|
term = var | number |
|
comparison_expr = term + comp_oper + term |
|
print(comparison_expr.searchString("B = 12 AA=23 B<=AA AA>12")) |
|
prints:: |
|
[['B', '=', '12'], ['AA', '=', '23'], ['B', '<=', 'AA'], ['AA', '>', '12']] |
|
""" |
|
if caseless: |
|
isequal = ( lambda a,b: a.upper() == b.upper() ) |
|
masks = ( lambda a,b: b.upper().startswith(a.upper()) ) |
|
parseElementClass = CaselessLiteral |
|
else: |
|
isequal = ( lambda a,b: a == b ) |
|
masks = ( lambda a,b: b.startswith(a) ) |
|
parseElementClass = Literal |
|
|
|
symbols = [] |
|
if isinstance(strs,basestring): |
|
symbols = strs.split() |
|
elif isinstance(strs, Iterable): |
|
symbols = list(strs) |
|
else: |
|
warnings.warn("Invalid argument to oneOf, expected string or iterable", |
|
SyntaxWarning, stacklevel=2) |
|
if not symbols: |
|
return NoMatch() |
|
|
|
i = 0 |
|
while i < len(symbols)-1: |
|
cur = symbols[i] |
|
for j,other in enumerate(symbols[i+1:]): |
|
if ( isequal(other, cur) ): |
|
del symbols[i+j+1] |
|
break |
|
elif ( masks(cur, other) ): |
|
del symbols[i+j+1] |
|
symbols.insert(i,other) |
|
cur = other |
|
break |
|
else: |
|
i += 1 |
|
|
|
if not caseless and useRegex: |
|
#~ print (strs,"->", "|".join( [ _escapeRegexChars(sym) for sym in symbols] )) |
|
try: |
|
if len(symbols)==len("".join(symbols)): |
|
return Regex( "[%s]" % "".join(_escapeRegexRangeChars(sym) for sym in symbols) ).setName(' | '.join(symbols)) |
|
else: |
|
return Regex( "|".join(re.escape(sym) for sym in symbols) ).setName(' | '.join(symbols)) |
|
except Exception: |
|
warnings.warn("Exception creating Regex for oneOf, building MatchFirst", |
|
SyntaxWarning, stacklevel=2) |
|
|
|
|
|
# last resort, just use MatchFirst |
|
return MatchFirst(parseElementClass(sym) for sym in symbols).setName(' | '.join(symbols)) |
|
|
|
def dictOf( key, value ): |
|
""" |
|
Helper to easily and clearly define a dictionary by specifying the respective patterns |
|
for the key and value. Takes care of defining the C{L{Dict}}, C{L{ZeroOrMore}}, and C{L{Group}} tokens |
|
in the proper order. The key pattern can include delimiting markers or punctuation, |
|
as long as they are suppressed, thereby leaving the significant key text. The value |
|
pattern can include named results, so that the C{Dict} results can include named token |
|
fields. |
|
|
|
Example:: |
|
text = "shape: SQUARE posn: upper left color: light blue texture: burlap" |
|
attr_expr = (label + Suppress(':') + OneOrMore(data_word, stopOn=label).setParseAction(' '.join)) |
|
print(OneOrMore(attr_expr).parseString(text).dump()) |
|
|
|
attr_label = label |
|
attr_value = Suppress(':') + OneOrMore(data_word, stopOn=label).setParseAction(' '.join) |
|
|
|
# similar to Dict, but simpler call format |
|
result = dictOf(attr_label, attr_value).parseString(text) |
|
print(result.dump()) |
|
print(result['shape']) |
|
print(result.shape) # object attribute access works too |
|
print(result.asDict()) |
|
prints:: |
|
[['shape', 'SQUARE'], ['posn', 'upper left'], ['color', 'light blue'], ['texture', 'burlap']] |
|
- color: light blue |
|
- posn: upper left |
|
- shape: SQUARE |
|
- texture: burlap |
|
SQUARE |
|
SQUARE |
|
{'color': 'light blue', 'shape': 'SQUARE', 'posn': 'upper left', 'texture': 'burlap'} |
|
""" |
|
return Dict( ZeroOrMore( Group ( key + value ) ) ) |
|
|
|
def originalTextFor(expr, asString=True): |
|
""" |
|
Helper to return the original, untokenized text for a given expression. Useful to |
|
restore the parsed fields of an HTML start tag into the raw tag text itself, or to |
|
revert separate tokens with intervening whitespace back to the original matching |
|
input text. By default, returns astring containing the original parsed text. |
|
|
|
If the optional C{asString} argument is passed as C{False}, then the return value is a |
|
C{L{ParseResults}} containing any results names that were originally matched, and a |
|
single token containing the original matched text from the input string. So if |
|
the expression passed to C{L{originalTextFor}} contains expressions with defined |
|
results names, you must set C{asString} to C{False} if you want to preserve those |
|
results name values. |
|
|
|
Example:: |
|
src = "this is test <b> bold <i>text</i> </b> normal text " |
|
for tag in ("b","i"): |
|
opener,closer = makeHTMLTags(tag) |
|
patt = originalTextFor(opener + SkipTo(closer) + closer) |
|
print(patt.searchString(src)[0]) |
|
prints:: |
|
['<b> bold <i>text</i> </b>'] |
|
['<i>text</i>'] |
|
""" |
|
locMarker = Empty().setParseAction(lambda s,loc,t: loc) |
|
endlocMarker = locMarker.copy() |
|
endlocMarker.callPreparse = False |
|
matchExpr = locMarker("_original_start") + expr + endlocMarker("_original_end") |
|
if asString: |
|
extractText = lambda s,l,t: s[t._original_start:t._original_end] |
|
else: |
|
def extractText(s,l,t): |
|
t[:] = [s[t.pop('_original_start'):t.pop('_original_end')]] |
|
matchExpr.setParseAction(extractText) |
|
matchExpr.ignoreExprs = expr.ignoreExprs |
|
return matchExpr |
|
|
|
def ungroup(expr): |
|
""" |
|
Helper to undo pyparsing's default grouping of And expressions, even |
|
if all but one are non-empty. |
|
""" |
|
return TokenConverter(expr).setParseAction(lambda t:t[0]) |
|
|
|
def locatedExpr(expr): |
|
""" |
|
Helper to decorate a returned token with its starting and ending locations in the input string. |
|
This helper adds the following results names: |
|
- locn_start = location where matched expression begins |
|
- locn_end = location where matched expression ends |
|
- value = the actual parsed results |
|
|
|
Be careful if the input text contains C{<TAB>} characters, you may want to call |
|
C{L{ParserElement.parseWithTabs}} |
|
|
|
Example:: |
|
wd = Word(alphas) |
|
for match in locatedExpr(wd).searchString("ljsdf123lksdjjf123lkkjj1222"): |
|
print(match) |
|
prints:: |
|
[[0, 'ljsdf', 5]] |
|
[[8, 'lksdjjf', 15]] |
|
[[18, 'lkkjj', 23]] |
|
""" |
|
locator = Empty().setParseAction(lambda s,l,t: l) |
|
return Group(locator("locn_start") + expr("value") + locator.copy().leaveWhitespace()("locn_end")) |
|
|
|
|
|
# convenience constants for positional expressions |
|
empty = Empty().setName("empty") |
|
lineStart = LineStart().setName("lineStart") |
|
lineEnd = LineEnd().setName("lineEnd") |
|
stringStart = StringStart().setName("stringStart") |
|
stringEnd = StringEnd().setName("stringEnd") |
|
|
|
_escapedPunc = Word( _bslash, r"\[]-*.$+^?()~ ", exact=2 ).setParseAction(lambda s,l,t:t[0][1]) |
|
_escapedHexChar = Regex(r"\\0?[xX][0-9a-fA-F]+").setParseAction(lambda s,l,t:unichr(int(t[0].lstrip(r'\0x'),16))) |
|
_escapedOctChar = Regex(r"\\0[0-7]+").setParseAction(lambda s,l,t:unichr(int(t[0][1:],8))) |
|
_singleChar = _escapedPunc | _escapedHexChar | _escapedOctChar | CharsNotIn(r'\]', exact=1) |
|
_charRange = Group(_singleChar + Suppress("-") + _singleChar) |
|
_reBracketExpr = Literal("[") + Optional("^").setResultsName("negate") + Group( OneOrMore( _charRange | _singleChar ) ).setResultsName("body") + "]" |
|
|
|
def srange(s): |
|
r""" |
|
Helper to easily define string ranges for use in Word construction. Borrows |
|
syntax from regexp '[]' string range definitions:: |
|
srange("[0-9]") -> "0123456789" |
|
srange("[a-z]") -> "abcdefghijklmnopqrstuvwxyz" |
|
srange("[a-z$_]") -> "abcdefghijklmnopqrstuvwxyz$_" |
|
The input string must be enclosed in []'s, and the returned string is the expanded |
|
character set joined into a single string. |
|
The values enclosed in the []'s may be: |
|
- a single character |
|
- an escaped character with a leading backslash (such as C{\-} or C{\]}) |
|
- an escaped hex character with a leading C{'\x'} (C{\x21}, which is a C{'!'} character) |
|
(C{\0x##} is also supported for backwards compatibility) |
|
- an escaped octal character with a leading C{'\0'} (C{\041}, which is a C{'!'} character) |
|
- a range of any of the above, separated by a dash (C{'a-z'}, etc.) |
|
- any combination of the above (C{'aeiouy'}, C{'a-zA-Z0-9_$'}, etc.) |
|
""" |
|
_expanded = lambda p: p if not isinstance(p,ParseResults) else ''.join(unichr(c) for c in range(ord(p[0]),ord(p[1])+1)) |
|
try: |
|
return "".join(_expanded(part) for part in _reBracketExpr.parseString(s).body) |
|
except Exception: |
|
return "" |
|
|
|
def matchOnlyAtCol(n): |
|
""" |
|
Helper method for defining parse actions that require matching at a specific |
|
column in the input text. |
|
""" |
|
def verifyCol(strg,locn,toks): |
|
if col(locn,strg) != n: |
|
raise ParseException(strg,locn,"matched token not at column %d" % n) |
|
return verifyCol |
|
|
|
def replaceWith(replStr): |
|
""" |
|
Helper method for common parse actions that simply return a literal value. Especially |
|
useful when used with C{L{transformString<ParserElement.transformString>}()}. |
|
|
|
Example:: |
|
num = Word(nums).setParseAction(lambda toks: int(toks[0])) |
|
na = oneOf("N/A NA").setParseAction(replaceWith(math.nan)) |
|
term = na | num |
|
|
|
OneOrMore(term).parseString("324 234 N/A 234") # -> [324, 234, nan, 234] |
|
""" |
|
return lambda s,l,t: [replStr] |
|
|
|
def removeQuotes(s,l,t): |
|
""" |
|
Helper parse action for removing quotation marks from parsed quoted strings. |
|
|
|
Example:: |
|
# by default, quotation marks are included in parsed results |
|
quotedString.parseString("'Now is the Winter of our Discontent'") # -> ["'Now is the Winter of our Discontent'"] |
|
|
|
# use removeQuotes to strip quotation marks from parsed results |
|
quotedString.setParseAction(removeQuotes) |
|
quotedString.parseString("'Now is the Winter of our Discontent'") # -> ["Now is the Winter of our Discontent"] |
|
""" |
|
return t[0][1:-1] |
|
|
|
def tokenMap(func, *args): |
|
""" |
|
Helper to define a parse action by mapping a function to all elements of a ParseResults list.If any additional |
|
args are passed, they are forwarded to the given function as additional arguments after |
|
the token, as in C{hex_integer = Word(hexnums).setParseAction(tokenMap(int, 16))}, which will convert the |
|
parsed data to an integer using base 16. |
|
|
|
Example (compare the last to example in L{ParserElement.transformString}:: |
|
hex_ints = OneOrMore(Word(hexnums)).setParseAction(tokenMap(int, 16)) |
|
hex_ints.runTests(''' |
|
00 11 22 aa FF 0a 0d 1a |
|
''') |
|
|
|
upperword = Word(alphas).setParseAction(tokenMap(str.upper)) |
|
OneOrMore(upperword).runTests(''' |
|
my kingdom for a horse |
|
''') |
|
|
|
wd = Word(alphas).setParseAction(tokenMap(str.title)) |
|
OneOrMore(wd).setParseAction(' '.join).runTests(''' |
|
now is the winter of our discontent made glorious summer by this sun of york |
|
''') |
|
prints:: |
|
00 11 22 aa FF 0a 0d 1a |
|
[0, 17, 34, 170, 255, 10, 13, 26] |
|
|
|
my kingdom for a horse |
|
['MY', 'KINGDOM', 'FOR', 'A', 'HORSE'] |
|
|
|
now is the winter of our discontent made glorious summer by this sun of york |
|
['Now Is The Winter Of Our Discontent Made Glorious Summer By This Sun Of York'] |
|
""" |
|
def pa(s,l,t): |
|
return [func(tokn, *args) for tokn in t] |
|
|
|
try: |
|
func_name = getattr(func, '__name__', |
|
getattr(func, '__class__').__name__) |
|
except Exception: |
|
func_name = str(func) |
|
pa.__name__ = func_name |
|
|
|
return pa |
|
|
|
upcaseTokens = tokenMap(lambda t: _ustr(t).upper()) |
|
"""(Deprecated) Helper parse action to convert tokens to upper case. Deprecated in favor of L{pyparsing_common.upcaseTokens}""" |
|
|
|
downcaseTokens = tokenMap(lambda t: _ustr(t).lower()) |
|
"""(Deprecated) Helper parse action to convert tokens to lower case. Deprecated in favor of L{pyparsing_common.downcaseTokens}""" |
|
|
|
def _makeTags(tagStr, xml): |
|
"""Internal helper to construct opening and closing tag expressions, given a tag name""" |
|
if isinstance(tagStr,basestring): |
|
resname = tagStr |
|
tagStr = Keyword(tagStr, caseless=not xml) |
|
else: |
|
resname = tagStr.name |
|
|
|
tagAttrName = Word(alphas,alphanums+"_-:") |
|
if (xml): |
|
tagAttrValue = dblQuotedString.copy().setParseAction( removeQuotes ) |
|
openTag = Suppress("<") + tagStr("tag") + \ |
|
Dict(ZeroOrMore(Group( tagAttrName + Suppress("=") + tagAttrValue ))) + \ |
|
Optional("/",default=[False]).setResultsName("empty").setParseAction(lambda s,l,t:t[0]=='/') + Suppress(">") |
|
else: |
|
printablesLessRAbrack = "".join(c for c in printables if c not in ">") |
|
tagAttrValue = quotedString.copy().setParseAction( removeQuotes ) | Word(printablesLessRAbrack) |
|
openTag = Suppress("<") + tagStr("tag") + \ |
|
Dict(ZeroOrMore(Group( tagAttrName.setParseAction(downcaseTokens) + \ |
|
Optional( Suppress("=") + tagAttrValue ) ))) + \ |
|
Optional("/",default=[False]).setResultsName("empty").setParseAction(lambda s,l,t:t[0]=='/') + Suppress(">") |
|
closeTag = Combine(_L("</") + tagStr + ">") |
|
|
|
openTag = openTag.setResultsName("start"+"".join(resname.replace(":"," ").title().split())).setName("<%s>" % resname) |
|
closeTag = closeTag.setResultsName("end"+"".join(resname.replace(":"," ").title().split())).setName("</%s>" % resname) |
|
openTag.tag = resname |
|
closeTag.tag = resname |
|
return openTag, closeTag |
|
|
|
def makeHTMLTags(tagStr): |
|
""" |
|
Helper to construct opening and closing tag expressions for HTML, given a tag name. Matches |
|
tags in either upper or lower case, attributes with namespaces and with quoted or unquoted values. |
|
|
|
Example:: |
|
text = '<td>More info at the <a href="http://pyparsing.wikispaces.com">pyparsing</a> wiki page</td>' |
|
# makeHTMLTags returns pyparsing expressions for the opening and closing tags as a 2-tuple |
|
a,a_end = makeHTMLTags("A") |
|
link_expr = a + SkipTo(a_end)("link_text") + a_end |
|
|
|
for link in link_expr.searchString(text): |
|
# attributes in the <A> tag (like "href" shown here) are also accessible as named results |
|
print(link.link_text, '->', link.href) |
|
prints:: |
|
pyparsing -> http://pyparsing.wikispaces.com |
|
""" |
|
return _makeTags( tagStr, False ) |
|
|
|
def makeXMLTags(tagStr): |
|
""" |
|
Helper to construct opening and closing tag expressions for XML, given a tag name. Matches |
|
tags only in the given upper/lower case. |
|
|
|
Example: similar to L{makeHTMLTags} |
|
""" |
|
return _makeTags( tagStr, True ) |
|
|
|
def withAttribute(*args,**attrDict): |
|
""" |
|
Helper to create a validating parse action to be used with start tags created |
|
with C{L{makeXMLTags}} or C{L{makeHTMLTags}}. Use C{withAttribute} to qualify a starting tag |
|
with a required attribute value, to avoid false matches on common tags such as |
|
C{<TD>} or C{<DIV>}. |
|
|
|
Call C{withAttribute} with a series of attribute names and values. Specify the list |
|
of filter attributes names and values as: |
|
- keyword arguments, as in C{(align="right")}, or |
|
- as an explicit dict with C{**} operator, when an attribute name is also a Python |
|
reserved word, as in C{**{"class":"Customer", "align":"right"}} |
|
- a list of name-value tuples, as in ( ("ns1:class", "Customer"), ("ns2:align","right") ) |
|
For attribute names with a namespace prefix, you must use the second form. Attribute |
|
names are matched insensitive to upper/lower case. |
|
|
|
If just testing for C{class} (with or without a namespace), use C{L{withClass}}. |
|
|
|
To verify that the attribute exists, but without specifying a value, pass |
|
C{withAttribute.ANY_VALUE} as the value. |
|
|
|
Example:: |
|
html = ''' |
|
<div> |
|
Some text |
|
<div type="grid">1 4 0 1 0</div> |
|
<div type="graph">1,3 2,3 1,1</div> |
|
<div>this has no type</div> |
|
</div> |
|
|
|
''' |
|
div,div_end = makeHTMLTags("div") |
|
|
|
# only match div tag having a type attribute with value "grid" |
|
div_grid = div().setParseAction(withAttribute(type="grid")) |
|
grid_expr = div_grid + SkipTo(div | div_end)("body") |
|
for grid_header in grid_expr.searchString(html): |
|
print(grid_header.body) |
|
|
|
# construct a match with any div tag having a type attribute, regardless of the value |
|
div_any_type = div().setParseAction(withAttribute(type=withAttribute.ANY_VALUE)) |
|
div_expr = div_any_type + SkipTo(div | div_end)("body") |
|
for div_header in div_expr.searchString(html): |
|
print(div_header.body) |
|
prints:: |
|
1 4 0 1 0 |
|
|
|
1 4 0 1 0 |
|
1,3 2,3 1,1 |
|
""" |
|
if args: |
|
attrs = args[:] |
|
else: |
|
attrs = attrDict.items() |
|
attrs = [(k,v) for k,v in attrs] |
|
def pa(s,l,tokens): |
|
for attrName,attrValue in attrs: |
|
if attrName not in tokens: |
|
raise ParseException(s,l,"no matching attribute " + attrName) |
|
if attrValue != withAttribute.ANY_VALUE and tokens[attrName] != attrValue: |
|
raise ParseException(s,l,"attribute '%s' has value '%s', must be '%s'" % |
|
(attrName, tokens[attrName], attrValue)) |
|
return pa |
|
withAttribute.ANY_VALUE = object() |
|
|
|
def withClass(classname, namespace=''): |
|
""" |
|
Simplified version of C{L{withAttribute}} when matching on a div class - made |
|
difficult because C{class} is a reserved word in Python. |
|
|
|
Example:: |
|
html = ''' |
|
<div> |
|
Some text |
|
<div class="grid">1 4 0 1 0</div> |
|
<div class="graph">1,3 2,3 1,1</div> |
|
<div>this <div> has no class</div> |
|
</div> |
|
|
|
''' |
|
div,div_end = makeHTMLTags("div") |
|
div_grid = div().setParseAction(withClass("grid")) |
|
|
|
grid_expr = div_grid + SkipTo(div | div_end)("body") |
|
for grid_header in grid_expr.searchString(html): |
|
print(grid_header.body) |
|
|
|
div_any_type = div().setParseAction(withClass(withAttribute.ANY_VALUE)) |
|
div_expr = div_any_type + SkipTo(div | div_end)("body") |
|
for div_header in div_expr.searchString(html): |
|
print(div_header.body) |
|
prints:: |
|
1 4 0 1 0 |
|
|
|
1 4 0 1 0 |
|
1,3 2,3 1,1 |
|
""" |
|
classattr = "%s:class" % namespace if namespace else "class" |
|
return withAttribute(**{classattr : classname}) |
|
|
|
opAssoc = _Constants() |
|
opAssoc.LEFT = object() |
|
opAssoc.RIGHT = object() |
|
|
|
def infixNotation( baseExpr, opList, lpar=Suppress('('), rpar=Suppress(')') ): |
|
""" |
|
Helper method for constructing grammars of expressions made up of |
|
operators working in a precedence hierarchy. Operators may be unary or |
|
binary, left- or right-associative. Parse actions can also be attached |
|
to operator expressions. The generated parser will also recognize the use |
|
of parentheses to override operator precedences (see example below). |
|
|
|
Note: if you define a deep operator list, you may see performance issues |
|
when using infixNotation. See L{ParserElement.enablePackrat} for a |
|
mechanism to potentially improve your parser performance. |
|
|
|
Parameters: |
|
- baseExpr - expression representing the most basic element for the nested |
|
- opList - list of tuples, one for each operator precedence level in the |
|
expression grammar; each tuple is of the form |
|
(opExpr, numTerms, rightLeftAssoc, parseAction), where: |
|
- opExpr is the pyparsing expression for the operator; |
|
may also be a string, which will be converted to a Literal; |
|
if numTerms is 3, opExpr is a tuple of two expressions, for the |
|
two operators separating the 3 terms |
|
- numTerms is the number of terms for this operator (must |
|
be 1, 2, or 3) |
|
- rightLeftAssoc is the indicator whether the operator is |
|
right or left associative, using the pyparsing-defined |
|
constants C{opAssoc.RIGHT} and C{opAssoc.LEFT}. |
|
- parseAction is the parse action to be associated with |
|
expressions matching this operator expression (the |
|
parse action tuple member may be omitted); if the parse action |
|
is passed a tuple or list of functions, this is equivalent to |
|
calling C{setParseAction(*fn)} (L{ParserElement.setParseAction}) |
|
- lpar - expression for matching left-parentheses (default=C{Suppress('(')}) |
|
- rpar - expression for matching right-parentheses (default=C{Suppress(')')}) |
|
|
|
Example:: |
|
# simple example of four-function arithmetic with ints and variable names |
|
integer = pyparsing_common.signed_integer |
|
varname = pyparsing_common.identifier |
|
|
|
arith_expr = infixNotation(integer | varname, |
|
[ |
|
('-', 1, opAssoc.RIGHT), |
|
(oneOf('* /'), 2, opAssoc.LEFT), |
|
(oneOf('+ -'), 2, opAssoc.LEFT), |
|
]) |
|
|
|
arith_expr.runTests(''' |
|
5+3*6 |
|
(5+3)*6 |
|
-2--11 |
|
''', fullDump=False) |
|
prints:: |
|
5+3*6 |
|
[[5, '+', [3, '*', 6]]] |
|
|
|
(5+3)*6 |
|
[[[5, '+', 3], '*', 6]] |
|
|
|
-2--11 |
|
[[['-', 2], '-', ['-', 11]]] |
|
""" |
|
ret = Forward() |
|
lastExpr = baseExpr | ( lpar + ret + rpar ) |
|
for i,operDef in enumerate(opList): |
|
opExpr,arity,rightLeftAssoc,pa = (operDef + (None,))[:4] |
|
termName = "%s term" % opExpr if arity < 3 else "%s%s term" % opExpr |
|
if arity == 3: |
|
if opExpr is None or len(opExpr) != 2: |
|
raise ValueError("if numterms=3, opExpr must be a tuple or list of two expressions") |
|
opExpr1, opExpr2 = opExpr |
|
thisExpr = Forward().setName(termName) |
|
if rightLeftAssoc == opAssoc.LEFT: |
|
if arity == 1: |
|
matchExpr = FollowedBy(lastExpr + opExpr) + Group( lastExpr + OneOrMore( opExpr ) ) |
|
elif arity == 2: |
|
if opExpr is not None: |
|
matchExpr = FollowedBy(lastExpr + opExpr + lastExpr) + Group( lastExpr + OneOrMore( opExpr + lastExpr ) ) |
|
else: |
|
matchExpr = FollowedBy(lastExpr+lastExpr) + Group( lastExpr + OneOrMore(lastExpr) ) |
|
elif arity == 3: |
|
matchExpr = FollowedBy(lastExpr + opExpr1 + lastExpr + opExpr2 + lastExpr) + \ |
|
Group( lastExpr + opExpr1 + lastExpr + opExpr2 + lastExpr ) |
|
else: |
|
raise ValueError("operator must be unary (1), binary (2), or ternary (3)") |
|
elif rightLeftAssoc == opAssoc.RIGHT: |
|
if arity == 1: |
|
# try to avoid LR with this extra test |
|
if not isinstance(opExpr, Optional): |
|
opExpr = Optional(opExpr) |
|
matchExpr = FollowedBy(opExpr.expr + thisExpr) + Group( opExpr + thisExpr ) |
|
elif arity == 2: |
|
if opExpr is not None: |
|
matchExpr = FollowedBy(lastExpr + opExpr + thisExpr) + Group( lastExpr + OneOrMore( opExpr + thisExpr ) ) |
|
else: |
|
matchExpr = FollowedBy(lastExpr + thisExpr) + Group( lastExpr + OneOrMore( thisExpr ) ) |
|
elif arity == 3: |
|
matchExpr = FollowedBy(lastExpr + opExpr1 + thisExpr + opExpr2 + thisExpr) + \ |
|
Group( lastExpr + opExpr1 + thisExpr + opExpr2 + thisExpr ) |
|
else: |
|
raise ValueError("operator must be unary (1), binary (2), or ternary (3)") |
|
else: |
|
raise ValueError("operator must indicate right or left associativity") |
|
if pa: |
|
if isinstance(pa, (tuple, list)): |
|
matchExpr.setParseAction(*pa) |
|
else: |
|
matchExpr.setParseAction(pa) |
|
thisExpr <<= ( matchExpr.setName(termName) | lastExpr ) |
|
lastExpr = thisExpr |
|
ret <<= lastExpr |
|
return ret |
|
|
|
operatorPrecedence = infixNotation |
|
"""(Deprecated) Former name of C{L{infixNotation}}, will be dropped in a future release.""" |
|
|
|
dblQuotedString = Combine(Regex(r'"(?:[^"\n\r\\]|(?:"")|(?:\\(?:[^x]|x[0-9a-fA-F]+)))*')+'"').setName("string enclosed in double quotes") |
|
sglQuotedString = Combine(Regex(r"'(?:[^'\n\r\\]|(?:'')|(?:\\(?:[^x]|x[0-9a-fA-F]+)))*")+"'").setName("string enclosed in single quotes") |
|
quotedString = Combine(Regex(r'"(?:[^"\n\r\\]|(?:"")|(?:\\(?:[^x]|x[0-9a-fA-F]+)))*')+'"'| |
|
Regex(r"'(?:[^'\n\r\\]|(?:'')|(?:\\(?:[^x]|x[0-9a-fA-F]+)))*")+"'").setName("quotedString using single or double quotes") |
|
unicodeString = Combine(_L('u') + quotedString.copy()).setName("unicode string literal") |
|
|
|
def nestedExpr(opener="(", closer=")", content=None, ignoreExpr=quotedString.copy()): |
|
""" |
|
Helper method for defining nested lists enclosed in opening and closing |
|
delimiters ("(" and ")" are the default). |
|
|
|
Parameters: |
|
- opener - opening character for a nested list (default=C{"("}); can also be a pyparsing expression |
|
- closer - closing character for a nested list (default=C{")"}); can also be a pyparsing expression |
|
- content - expression for items within the nested lists (default=C{None}) |
|
- ignoreExpr - expression for ignoring opening and closing delimiters (default=C{quotedString}) |
|
|
|
If an expression is not provided for the content argument, the nested |
|
expression will capture all whitespace-delimited content between delimiters |
|
as a list of separate values. |
|
|
|
Use the C{ignoreExpr} argument to define expressions that may contain |
|
opening or closing characters that should not be treated as opening |
|
or closing characters for nesting, such as quotedString or a comment |
|
expression. Specify multiple expressions using an C{L{Or}} or C{L{MatchFirst}}. |
|
The default is L{quotedString}, but if no expressions are to be ignored, |
|
then pass C{None} for this argument. |
|
|
|
Example:: |
|
data_type = oneOf("void int short long char float double") |
|
decl_data_type = Combine(data_type + Optional(Word('*'))) |
|
ident = Word(alphas+'_', alphanums+'_') |
|
number = pyparsing_common.number |
|
arg = Group(decl_data_type + ident) |
|
LPAR,RPAR = map(Suppress, "()") |
|
|
|
code_body = nestedExpr('{', '}', ignoreExpr=(quotedString | cStyleComment)) |
|
|
|
c_function = (decl_data_type("type") |
|
+ ident("name") |
|
+ LPAR + Optional(delimitedList(arg), [])("args") + RPAR |
|
+ code_body("body")) |
|
c_function.ignore(cStyleComment) |
|
|
|
source_code = ''' |
|
int is_odd(int x) { |
|
return (x%2); |
|
} |
|
|
|
int dec_to_hex(char hchar) { |
|
if (hchar >= '0' && hchar <= '9') { |
|
return (ord(hchar)-ord('0')); |
|
} else { |
|
return (10+ord(hchar)-ord('A')); |
|
} |
|
} |
|
''' |
|
for func in c_function.searchString(source_code): |
|
print("%(name)s (%(type)s) args: %(args)s" % func) |
|
|
|
prints:: |
|
is_odd (int) args: [['int', 'x']] |
|
dec_to_hex (int) args: [['char', 'hchar']] |
|
""" |
|
if opener == closer: |
|
raise ValueError("opening and closing strings cannot be the same") |
|
if content is None: |
|
if isinstance(opener,basestring) and isinstance(closer,basestring): |
|
if len(opener) == 1 and len(closer)==1: |
|
if ignoreExpr is not None: |
|
content = (Combine(OneOrMore(~ignoreExpr + |
|
CharsNotIn(opener+closer+ParserElement.DEFAULT_WHITE_CHARS,exact=1)) |
|
).setParseAction(lambda t:t[0].strip())) |
|
else: |
|
content = (empty.copy()+CharsNotIn(opener+closer+ParserElement.DEFAULT_WHITE_CHARS |
|
).setParseAction(lambda t:t[0].strip())) |
|
else: |
|
if ignoreExpr is not None: |
|
content = (Combine(OneOrMore(~ignoreExpr + |
|
~Literal(opener) + ~Literal(closer) + |
|
CharsNotIn(ParserElement.DEFAULT_WHITE_CHARS,exact=1)) |
|
).setParseAction(lambda t:t[0].strip())) |
|
else: |
|
content = (Combine(OneOrMore(~Literal(opener) + ~Literal(closer) + |
|
CharsNotIn(ParserElement.DEFAULT_WHITE_CHARS,exact=1)) |
|
).setParseAction(lambda t:t[0].strip())) |
|
else: |
|
raise ValueError("opening and closing arguments must be strings if no content expression is given") |
|
ret = Forward() |
|
if ignoreExpr is not None: |
|
ret <<= Group( Suppress(opener) + ZeroOrMore( ignoreExpr | ret | content ) + Suppress(closer) ) |
|
else: |
|
ret <<= Group( Suppress(opener) + ZeroOrMore( ret | content ) + Suppress(closer) ) |
|
ret.setName('nested %s%s expression' % (opener,closer)) |
|
return ret |
|
|
|
def indentedBlock(blockStatementExpr, indentStack, indent=True): |
|
""" |
|
Helper method for defining space-delimited indentation blocks, such as |
|
those used to define block statements in Python source code. |
|
|
|
Parameters: |
|
- blockStatementExpr - expression defining syntax of statement that |
|
is repeated within the indented block |
|
- indentStack - list created by caller to manage indentation stack |
|
(multiple statementWithIndentedBlock expressions within a single grammar |
|
should share a common indentStack) |
|
- indent - boolean indicating whether block must be indented beyond the |
|
the current level; set to False for block of left-most statements |
|
(default=C{True}) |
|
|
|
A valid block must contain at least one C{blockStatement}. |
|
|
|
Example:: |
|
data = ''' |
|
def A(z): |
|
A1 |
|
B = 100 |
|
G = A2 |
|
A2 |
|
A3 |
|
B |
|
def BB(a,b,c): |
|
BB1 |
|
def BBA(): |
|
bba1 |
|
bba2 |
|
bba3 |
|
C |
|
D |
|
def spam(x,y): |
|
def eggs(z): |
|
pass |
|
''' |
|
|
|
|
|
indentStack = [1] |
|
stmt = Forward() |
|
|
|
identifier = Word(alphas, alphanums) |
|
funcDecl = ("def" + identifier + Group( "(" + Optional( delimitedList(identifier) ) + ")" ) + ":") |
|
func_body = indentedBlock(stmt, indentStack) |
|
funcDef = Group( funcDecl + func_body ) |
|
|
|
rvalue = Forward() |
|
funcCall = Group(identifier + "(" + Optional(delimitedList(rvalue)) + ")") |
|
rvalue << (funcCall | identifier | Word(nums)) |
|
assignment = Group(identifier + "=" + rvalue) |
|
stmt << ( funcDef | assignment | identifier ) |
|
|
|
module_body = OneOrMore(stmt) |
|
|
|
parseTree = module_body.parseString(data) |
|
parseTree.pprint() |
|
prints:: |
|
[['def', |
|
'A', |
|
['(', 'z', ')'], |
|
':', |
|
[['A1'], [['B', '=', '100']], [['G', '=', 'A2']], ['A2'], ['A3']]], |
|
'B', |
|
['def', |
|
'BB', |
|
['(', 'a', 'b', 'c', ')'], |
|
':', |
|
[['BB1'], [['def', 'BBA', ['(', ')'], ':', [['bba1'], ['bba2'], ['bba3']]]]]], |
|
'C', |
|
'D', |
|
['def', |
|
'spam', |
|
['(', 'x', 'y', ')'], |
|
':', |
|
[[['def', 'eggs', ['(', 'z', ')'], ':', [['pass']]]]]]] |
|
""" |
|
def checkPeerIndent(s,l,t): |
|
if l >= len(s): return |
|
curCol = col(l,s) |
|
if curCol != indentStack[-1]: |
|
if curCol > indentStack[-1]: |
|
raise ParseFatalException(s,l,"illegal nesting") |
|
raise ParseException(s,l,"not a peer entry") |
|
|
|
def checkSubIndent(s,l,t): |
|
curCol = col(l,s) |
|
if curCol > indentStack[-1]: |
|
indentStack.append( curCol ) |
|
else: |
|
raise ParseException(s,l,"not a subentry") |
|
|
|
def checkUnindent(s,l,t): |
|
if l >= len(s): return |
|
curCol = col(l,s) |
|
if not(indentStack and curCol < indentStack[-1] and curCol <= indentStack[-2]): |
|
raise ParseException(s,l,"not an unindent") |
|
indentStack.pop() |
|
|
|
NL = OneOrMore(LineEnd().setWhitespaceChars("\t ").suppress()) |
|
INDENT = (Empty() + Empty().setParseAction(checkSubIndent)).setName('INDENT') |
|
PEER = Empty().setParseAction(checkPeerIndent).setName('') |
|
UNDENT = Empty().setParseAction(checkUnindent).setName('UNINDENT') |
|
if indent: |
|
smExpr = Group( Optional(NL) + |
|
#~ FollowedBy(blockStatementExpr) + |
|
INDENT + (OneOrMore( PEER + Group(blockStatementExpr) + Optional(NL) )) + UNDENT) |
|
else: |
|
smExpr = Group( Optional(NL) + |
|
(OneOrMore( PEER + Group(blockStatementExpr) + Optional(NL) )) ) |
|
blockStatementExpr.ignore(_bslash + LineEnd()) |
|
return smExpr.setName('indented block') |
|
|
|
alphas8bit = srange(r"[\0xc0-\0xd6\0xd8-\0xf6\0xf8-\0xff]") |
|
punc8bit = srange(r"[\0xa1-\0xbf\0xd7\0xf7]") |
|
|
|
anyOpenTag,anyCloseTag = makeHTMLTags(Word(alphas,alphanums+"_:").setName('any tag')) |
|
_htmlEntityMap = dict(zip("gt lt amp nbsp quot apos".split(),'><& "\'')) |
|
commonHTMLEntity = Regex('&(?P<entity>' + '|'.join(_htmlEntityMap.keys()) +");").setName("common HTML entity") |
|
def replaceHTMLEntity(t): |
|
"""Helper parser action to replace common HTML entities with their special characters""" |
|
return _htmlEntityMap.get(t.entity) |
|
|
|
# it's easy to get these comment structures wrong - they're very common, so may as well make them available |
|
cStyleComment = Combine(Regex(r"/\*(?:[^*]|\*(?!/))*") + '*/').setName("C style comment") |
|
"Comment of the form C{/* ... */}" |
|
|
|
htmlComment = Regex(r"<!--[\s\S]*?-->").setName("HTML comment") |
|
"Comment of the form C{<!-- ... -->}" |
|
|
|
restOfLine = Regex(r".*").leaveWhitespace().setName("rest of line") |
|
dblSlashComment = Regex(r"//(?:\\\n|[^\n])*").setName("// comment") |
|
"Comment of the form C{// ... (to end of line)}" |
|
|
|
cppStyleComment = Combine(Regex(r"/\*(?:[^*]|\*(?!/))*") + '*/'| dblSlashComment).setName("C++ style comment") |
|
"Comment of either form C{L{cStyleComment}} or C{L{dblSlashComment}}" |
|
|
|
javaStyleComment = cppStyleComment |
|
"Same as C{L{cppStyleComment}}" |
|
|
|
pythonStyleComment = Regex(r"#.*").setName("Python style comment") |
|
"Comment of the form C{# ... (to end of line)}" |
|
|
|
_commasepitem = Combine(OneOrMore(Word(printables, excludeChars=',') + |
|
Optional( Word(" \t") + |
|
~Literal(",") + ~LineEnd() ) ) ).streamline().setName("commaItem") |
|
commaSeparatedList = delimitedList( Optional( quotedString.copy() | _commasepitem, default="") ).setName("commaSeparatedList") |
|
"""(Deprecated) Predefined expression of 1 or more printable words or quoted strings, separated by commas. |
|
This expression is deprecated in favor of L{pyparsing_common.comma_separated_list}.""" |
|
|
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# some other useful expressions - using lower-case class name since we are really using this as a namespace |
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class pyparsing_common: |
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""" |
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Here are some common low-level expressions that may be useful in jump-starting parser development: |
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- numeric forms (L{integers<integer>}, L{reals<real>}, L{scientific notation<sci_real>}) |
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- common L{programming identifiers<identifier>} |
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- network addresses (L{MAC<mac_address>}, L{IPv4<ipv4_address>}, L{IPv6<ipv6_address>}) |
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- ISO8601 L{dates<iso8601_date>} and L{datetime<iso8601_datetime>} |
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- L{UUID<uuid>} |
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- L{comma-separated list<comma_separated_list>} |
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Parse actions: |
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- C{L{convertToInteger}} |
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- C{L{convertToFloat}} |
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- C{L{convertToDate}} |
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- C{L{convertToDatetime}} |
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- C{L{stripHTMLTags}} |
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- C{L{upcaseTokens}} |
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- C{L{downcaseTokens}} |
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|
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Example:: |
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pyparsing_common.number.runTests(''' |
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# any int or real number, returned as the appropriate type |
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100 |
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-100 |
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+100 |
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3.14159 |
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6.02e23 |
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1e-12 |
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''') |
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|
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pyparsing_common.fnumber.runTests(''' |
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# any int or real number, returned as float |
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100 |
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-100 |
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+100 |
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3.14159 |
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6.02e23 |
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1e-12 |
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''') |
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|
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pyparsing_common.hex_integer.runTests(''' |
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# hex numbers |
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100 |
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FF |
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''') |
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|
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pyparsing_common.fraction.runTests(''' |
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# fractions |
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1/2 |
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-3/4 |
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''') |
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|
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pyparsing_common.mixed_integer.runTests(''' |
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# mixed fractions |
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1 |
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1/2 |
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-3/4 |
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1-3/4 |
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''') |
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|
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import uuid |
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pyparsing_common.uuid.setParseAction(tokenMap(uuid.UUID)) |
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pyparsing_common.uuid.runTests(''' |
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# uuid |
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12345678-1234-5678-1234-567812345678 |
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''') |
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prints:: |
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# any int or real number, returned as the appropriate type |
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100 |
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[100] |
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|
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-100 |
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[-100] |
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|
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+100 |
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[100] |
|
|
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3.14159 |
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[3.14159] |
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|
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6.02e23 |
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[6.02e+23] |
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|
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1e-12 |
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[1e-12] |
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|
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# any int or real number, returned as float |
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100 |
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[100.0] |
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|
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-100 |
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[-100.0] |
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|
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+100 |
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[100.0] |
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|
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3.14159 |
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[3.14159] |
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|
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6.02e23 |
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[6.02e+23] |
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|
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1e-12 |
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[1e-12] |
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|
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# hex numbers |
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100 |
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[256] |
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|
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FF |
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[255] |
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|
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# fractions |
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1/2 |
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[0.5] |
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|
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-3/4 |
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[-0.75] |
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|
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# mixed fractions |
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1 |
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[1] |
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|
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1/2 |
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[0.5] |
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|
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-3/4 |
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[-0.75] |
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|
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1-3/4 |
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[1.75] |
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|
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# uuid |
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12345678-1234-5678-1234-567812345678 |
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[UUID('12345678-1234-5678-1234-567812345678')] |
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""" |
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|
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convertToInteger = tokenMap(int) |
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""" |
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Parse action for converting parsed integers to Python int |
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""" |
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|
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convertToFloat = tokenMap(float) |
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""" |
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Parse action for converting parsed numbers to Python float |
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""" |
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|
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integer = Word(nums).setName("integer").setParseAction(convertToInteger) |
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"""expression that parses an unsigned integer, returns an int""" |
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|
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hex_integer = Word(hexnums).setName("hex integer").setParseAction(tokenMap(int,16)) |
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"""expression that parses a hexadecimal integer, returns an int""" |
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|
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signed_integer = Regex(r'[+-]?\d+').setName("signed integer").setParseAction(convertToInteger) |
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"""expression that parses an integer with optional leading sign, returns an int""" |
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|
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fraction = (signed_integer().setParseAction(convertToFloat) + '/' + signed_integer().setParseAction(convertToFloat)).setName("fraction") |
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"""fractional expression of an integer divided by an integer, returns a float""" |
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fraction.addParseAction(lambda t: t[0]/t[-1]) |
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|
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mixed_integer = (fraction | signed_integer + Optional(Optional('-').suppress() + fraction)).setName("fraction or mixed integer-fraction") |
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"""mixed integer of the form 'integer - fraction', with optional leading integer, returns float""" |
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mixed_integer.addParseAction(sum) |
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|
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real = Regex(r'[+-]?\d+\.\d*').setName("real number").setParseAction(convertToFloat) |
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"""expression that parses a floating point number and returns a float""" |
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|
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sci_real = Regex(r'[+-]?\d+([eE][+-]?\d+|\.\d*([eE][+-]?\d+)?)').setName("real number with scientific notation").setParseAction(convertToFloat) |
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"""expression that parses a floating point number with optional scientific notation and returns a float""" |
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|
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# streamlining this expression makes the docs nicer-looking |
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number = (sci_real | real | signed_integer).streamline() |
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"""any numeric expression, returns the corresponding Python type""" |
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|
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fnumber = Regex(r'[+-]?\d+\.?\d*([eE][+-]?\d+)?').setName("fnumber").setParseAction(convertToFloat) |
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"""any int or real number, returned as float""" |
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|
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identifier = Word(alphas+'_', alphanums+'_').setName("identifier") |
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"""typical code identifier (leading alpha or '_', followed by 0 or more alphas, nums, or '_')""" |
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|
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ipv4_address = Regex(r'(25[0-5]|2[0-4][0-9]|1?[0-9]{1,2})(\.(25[0-5]|2[0-4][0-9]|1?[0-9]{1,2})){3}').setName("IPv4 address") |
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"IPv4 address (C{0.0.0.0 - 255.255.255.255})" |
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|
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_ipv6_part = Regex(r'[0-9a-fA-F]{1,4}').setName("hex_integer") |
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_full_ipv6_address = (_ipv6_part + (':' + _ipv6_part)*7).setName("full IPv6 address") |
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_short_ipv6_address = (Optional(_ipv6_part + (':' + _ipv6_part)*(0,6)) + "::" + Optional(_ipv6_part + (':' + _ipv6_part)*(0,6))).setName("short IPv6 address") |
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_short_ipv6_address.addCondition(lambda t: sum(1 for tt in t if pyparsing_common._ipv6_part.matches(tt)) < 8) |
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_mixed_ipv6_address = ("::ffff:" + ipv4_address).setName("mixed IPv6 address") |
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ipv6_address = Combine((_full_ipv6_address | _mixed_ipv6_address | _short_ipv6_address).setName("IPv6 address")).setName("IPv6 address") |
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"IPv6 address (long, short, or mixed form)" |
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|
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mac_address = Regex(r'[0-9a-fA-F]{2}([:.-])[0-9a-fA-F]{2}(?:\1[0-9a-fA-F]{2}){4}').setName("MAC address") |
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"MAC address xx:xx:xx:xx:xx (may also have '-' or '.' delimiters)" |
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|
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@staticmethod |
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def convertToDate(fmt="%Y-%m-%d"): |
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""" |
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Helper to create a parse action for converting parsed date string to Python datetime.date |
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|
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Params - |
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- fmt - format to be passed to datetime.strptime (default=C{"%Y-%m-%d"}) |
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|
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Example:: |
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date_expr = pyparsing_common.iso8601_date.copy() |
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date_expr.setParseAction(pyparsing_common.convertToDate()) |
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print(date_expr.parseString("1999-12-31")) |
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prints:: |
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[datetime.date(1999, 12, 31)] |
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""" |
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def cvt_fn(s,l,t): |
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try: |
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return datetime.strptime(t[0], fmt).date() |
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except ValueError as ve: |
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raise ParseException(s, l, str(ve)) |
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return cvt_fn |
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|
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@staticmethod |
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def convertToDatetime(fmt="%Y-%m-%dT%H:%M:%S.%f"): |
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""" |
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Helper to create a parse action for converting parsed datetime string to Python datetime.datetime |
|
|
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Params - |
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- fmt - format to be passed to datetime.strptime (default=C{"%Y-%m-%dT%H:%M:%S.%f"}) |
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|
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Example:: |
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dt_expr = pyparsing_common.iso8601_datetime.copy() |
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dt_expr.setParseAction(pyparsing_common.convertToDatetime()) |
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print(dt_expr.parseString("1999-12-31T23:59:59.999")) |
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prints:: |
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[datetime.datetime(1999, 12, 31, 23, 59, 59, 999000)] |
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""" |
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def cvt_fn(s,l,t): |
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try: |
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return datetime.strptime(t[0], fmt) |
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except ValueError as ve: |
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raise ParseException(s, l, str(ve)) |
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return cvt_fn |
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|
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iso8601_date = Regex(r'(?P<year>\d{4})(?:-(?P<month>\d\d)(?:-(?P<day>\d\d))?)?').setName("ISO8601 date") |
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"ISO8601 date (C{yyyy-mm-dd})" |
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|
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iso8601_datetime = Regex(r'(?P<year>\d{4})-(?P<month>\d\d)-(?P<day>\d\d)[T ](?P<hour>\d\d):(?P<minute>\d\d)(:(?P<second>\d\d(\.\d*)?)?)?(?P<tz>Z|[+-]\d\d:?\d\d)?').setName("ISO8601 datetime") |
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"ISO8601 datetime (C{yyyy-mm-ddThh:mm:ss.s(Z|+-00:00)}) - trailing seconds, milliseconds, and timezone optional; accepts separating C{'T'} or C{' '}" |
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|
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uuid = Regex(r'[0-9a-fA-F]{8}(-[0-9a-fA-F]{4}){3}-[0-9a-fA-F]{12}').setName("UUID") |
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"UUID (C{xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx})" |
|
|
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_html_stripper = anyOpenTag.suppress() | anyCloseTag.suppress() |
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@staticmethod |
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def stripHTMLTags(s, l, tokens): |
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""" |
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Parse action to remove HTML tags from web page HTML source |
|
|
|
Example:: |
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# strip HTML links from normal text |
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text = '<td>More info at the <a href="http://pyparsing.wikispaces.com">pyparsing</a> wiki page</td>' |
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td,td_end = makeHTMLTags("TD") |
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table_text = td + SkipTo(td_end).setParseAction(pyparsing_common.stripHTMLTags)("body") + td_end |
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|
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print(table_text.parseString(text).body) # -> 'More info at the pyparsing wiki page' |
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""" |
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return pyparsing_common._html_stripper.transformString(tokens[0]) |
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|
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_commasepitem = Combine(OneOrMore(~Literal(",") + ~LineEnd() + Word(printables, excludeChars=',') |
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+ Optional( White(" \t") ) ) ).streamline().setName("commaItem") |
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comma_separated_list = delimitedList( Optional( quotedString.copy() | _commasepitem, default="") ).setName("comma separated list") |
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"""Predefined expression of 1 or more printable words or quoted strings, separated by commas.""" |
|
|
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upcaseTokens = staticmethod(tokenMap(lambda t: _ustr(t).upper())) |
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"""Parse action to convert tokens to upper case.""" |
|
|
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downcaseTokens = staticmethod(tokenMap(lambda t: _ustr(t).lower())) |
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"""Parse action to convert tokens to lower case.""" |
|
|
|
|
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if __name__ == "__main__": |
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|
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selectToken = CaselessLiteral("select") |
|
fromToken = CaselessLiteral("from") |
|
|
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ident = Word(alphas, alphanums + "_$") |
|
|
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columnName = delimitedList(ident, ".", combine=True).setParseAction(upcaseTokens) |
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columnNameList = Group(delimitedList(columnName)).setName("columns") |
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columnSpec = ('*' | columnNameList) |
|
|
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tableName = delimitedList(ident, ".", combine=True).setParseAction(upcaseTokens) |
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tableNameList = Group(delimitedList(tableName)).setName("tables") |
|
|
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simpleSQL = selectToken("command") + columnSpec("columns") + fromToken + tableNameList("tables") |
|
|
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# demo runTests method, including embedded comments in test string |
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simpleSQL.runTests(""" |
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# '*' as column list and dotted table name |
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select * from SYS.XYZZY |
|
|
|
# caseless match on "SELECT", and casts back to "select" |
|
SELECT * from XYZZY, ABC |
|
|
|
# list of column names, and mixed case SELECT keyword |
|
Select AA,BB,CC from Sys.dual |
|
|
|
# multiple tables |
|
Select A, B, C from Sys.dual, Table2 |
|
|
|
# invalid SELECT keyword - should fail |
|
Xelect A, B, C from Sys.dual |
|
|
|
# incomplete command - should fail |
|
Select |
|
|
|
# invalid column name - should fail |
|
Select ^^^ frox Sys.dual |
|
|
|
""") |
|
|
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pyparsing_common.number.runTests(""" |
|
100 |
|
-100 |
|
+100 |
|
3.14159 |
|
6.02e23 |
|
1e-12 |
|
""") |
|
|
|
# any int or real number, returned as float |
|
pyparsing_common.fnumber.runTests(""" |
|
100 |
|
-100 |
|
+100 |
|
3.14159 |
|
6.02e23 |
|
1e-12 |
|
""") |
|
|
|
pyparsing_common.hex_integer.runTests(""" |
|
100 |
|
FF |
|
""") |
|
|
|
import uuid |
|
pyparsing_common.uuid.setParseAction(tokenMap(uuid.UUID)) |
|
pyparsing_common.uuid.runTests(""" |
|
12345678-1234-5678-1234-567812345678 |
|
""")
|
|
|