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PyParsing -- A Python Parsing Module
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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
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MIT License. See header of pyparsing.py

History
=======

See CHANGES file.

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