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==================================== PyParsing -- A Python Parsing Module ==================================== Introduction ============ The pyparsing module is an alternative approach to creating and executing simple grammars, vs. the traditional lex/yacc approach, or the use of regular expressions. The pyparsing module provides a library of classes that client code uses to construct the grammar directly in Python code. Here is a program to parse "Hello, World!" (or any greeting of the form "<salutation>, <addressee>!"): from pyparsing import Word, alphas greet = Word( alphas ) + "," + Word( alphas ) + "!" hello = "Hello, World!" print hello, "->", greet.parseString( hello ) The program outputs the following: Hello, World! -> ['Hello', ',', 'World', '!'] The Python representation of the grammar is quite readable, owing to the self-explanatory class names, and the use of '+', '|' and '^' operator definitions. The parsed results returned from parseString() can be accessed as a nested list, a dictionary, or an object with named attributes. The pyparsing module handles some of the problems that are typically vexing when writing text parsers: - extra or missing whitespace (the above program will also handle "Hello,World!", "Hello , World !", etc.) - quoted strings - embedded comments The .zip file includes examples of a simple SQL parser, simple CORBA IDL parser, a config file parser, a chemical formula parser, and a four- function algebraic notation parser. It also includes a simple how-to document, and a UML class diagram of the library's classes. Installation ============ Do the usual: python setup.py install (pyparsing requires Python 2.6 or later.) Or corresponding commands using pip, easy_install, or wheel: pip install pyparsing easy_install pyparsing wheel install pyparsing Documentation ============= See: HowToUsePyparsing.html License ======= MIT License. See header of pyparsing.py History ======= See CHANGES file.