"PyPy has alpha/beta-level support for the CPython C API, however, this feature is not yet complete. We strongly advise use of CFFI instead. CFFI come builtin with PyPy. Many libraries will require a bit of effort to work, but there are known success stories. Check out PyPy blog for updates, as well as the Compatibility Wiki. C extensions need to be recompiled for PyPy in order to work. Depending on your build system, it might work out of the box or will be slightly harder."