25.4. Pyrex
The Pyrex language (http://www.cosc.canterbury.ac.nz/~greg/python/Pyrex/) is often the most convenient way to write extensions for Python. Pyrex is a large subset of Python, with the addition of optional C-like types for variables: you can automatically compile Pyrex programs (source files with extension .pyx) into machine code (via an intermediate stage of generated C code), producing Python-importable extensions. See the above URL for all the details of Pyrex programming; in this section, I cover only a few essentials to let you get started with Pyrex.