header files for PyPy (an alternative Python 3.x interpreter)

 Header files for compiling cpython C extension modules for use with PyPy.
 Note that pure Python modules will probably perform better.
 .
 PyPy supports a subset of cpython's C API through its CPyExt subsystem.
 .
 PyPy is a fast, compliant alternative implementation of the Python language
 (3.x).