blockchain = [] def get_last_blockchain_value(): """ Returns the last value of the current blockchain. """ return blockchain[-1] def add_value(transaction_amount, last_transaction=[1]): """ Append a new value as well as the last blockchain value Arguments: :transaction_amount: The amount that should be added. :last_transaction: The last blockchain transaction (default[1]) """ blockchain.append([last_transaction, transaction_amount]) def get_user_input(): return float(input('Your transaction amount please')) tx_amount = get_user_input() add_value(tx_amount) tx_amount = get_user_input() add_value(tx_amount, get_last_blockchain_value()) print(blockchain)