Python Libraries

Python modules, plugins or libraries using the CPython API normally need to link against a library providing the symbols. Several versions of the library with distinct names may exist depending on build type (limited API, free threaded, etc).

The build type is indicated by defines like Py_LIMITED_API or Py_GIL_DISABLE.

UNIX

On these platforms, the symbol resolution is delayed and the symbols contained in the Python interpreter binary are used (requiring special options on macOS).

This works for Python modules and also for the Qt Widgets Designer plugin, in which case the symbols are provided by entry point pyside6-designer.

When embedding Python into an application, where no Python interpreter binary is available, the CPython library needs to be linked against.

There are only libraries for the normal (versioned) build; no CPython library for the limited API is provided.

The CPython documentation shows how to use tools like python3.13-config to obtain the correct flags.

Windows

On Windows, the delayed loading described above is not available and the CPython libraries need to be explicitly linked against for all use cases.

The header pyconfig.h contains a pragma with linking instructions for usage by the MSVC compiler, depending on the build type:

pragma comment(lib,"python3<14...>lib")

To explicitly specify the library by the build system instead, the define Py_NO_LINK_LIB can be set to disable the pragma.

Tools

The Shiboken6Tools CMake package provides the CMake macro shiboken_generator_create_binding, which is a convenient way of adding the libraries.