Python compatibility headers

pip install py3c==1.3



py3c helps you port C extensions to Python 3.

It provides a detailed guide, and a set of macros to make porting easy and reduce boilerplate.

Design principles

  • Reduce chances of accidental subtle errors
  • Minimize boilerplate
  • Prefer the Python 3 way of doing things
  • Minimize semantic changes under Python 2


Projects using py3c will be compatible with CPython 2.6, 2.7, and 3.3+.


A detailed porting guide is provided.

A cheatsheet is available for those that already know the Python C API, and want to know what the py3c macros do.


If your build system supports pkg-config, you can set it up to look for a system-wide installation of py3c.

Alternately, py3c can be used as a header-only library: copy the headers to your project and use them.

If you wish to install py3c system-wide (e.g. if you are a distro packager), see the Contributing chapter in the documentation.



The code is licensed under the MIT license. May it serve you well.

The documentation is licensed under CC-BY-SA 3.0.

See the files LICENSE.MIT and doc/LICENSE.CC-BY-SA-3.0.