An alternative for parsing - the pyparsing module

First download the package from here, unzip and run the installation command:

C:\pyparsing-1.5.5>python setup.py install
running install
running build
running build_py
creating build
creating build\lib
copying pyparsing.py -> build\lib
running install_lib
copying build\lib\pyparsing.py -> C:\Python27\Lib\site-packages
byte-compiling C:\Python27\Lib\site-packages\pyparsing.py to pyparsing.pyc
running install_egg_info
Writing C:\Python27\Lib\site-packages\pyparsing-1.5.5-py2.7.egg-info

From the official site we find that:

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.

The package comes with a number of examples that illustrate the flexibility of this module.
This file format is used by ICal on the Macintosh and in the Mozilla Calendar project. I think that can be imported into google calendar.

They can be found here.
Of these I particularly liked the example for parsing files with extension ics.