Pyrex is Python with C types. It is specially designed to allow you to write extension modules for Python that have the speed of C and the simplicity and readability of Python. You write your code in a Python-like language with C-typed variables, then use the pyrexc compiler to transform it into a C representation. This is useful for speeding up critical sections of your Python code or wrapping an external library.

Please see the documentation for how to get the best performance from your code.