This project is the python equivalent of google-gflags, a Google commandline flag implementation for C++. It is intended to be used in situations where a project wants to mimic the command-line flag handling of a C++ app that uses google-gflags, or for a Python app that, via swig or some other means, is linked with a C++ app that uses google-gflags.
The gflags package contains a library that implements commandline flags processing. As such it's a replacement for getopt(). It has increased flexibility, including built-in support for Python types, and the ability to define flags in the source file in which they're used. (This last is its major difference from OptParse.)