Python parsing module

 The parsing module is an alternative approach to creating and
 executing simple grammars, vs. the traditional lex/yacc approach, or
 the use of regular expressions. The parsing module provides a
 library of classes that client code uses to construct the grammar
 directly in Python code.
 .
 Here's an example:
 .
  from pyparsing import Word, alphas
  greet = Word(alphas) + "," + Word(alphas) + "!"
  hello = "Hello, World!"
  print hello, "->", greet.parseString(hello)