# FindPythonLibs

Changed in version 3.27: This module is available only if policy `CMP0148` is not set to `NEW`.

Deprecated since version 3.12: Use `FindPython3`, `FindPython2`, or `FindPython` instead.

This module finds the Python installation and determines the location of its include directories and libraries, as well as the name of the Python library to link against.

Note

When using both this and the `FindPythonInterp` module, call `find_package(PythonInterp)` before `find_package(PythonLibs)`. This ensures that the detected interpreter version is used to guide the selection of compatible libraries, resulting in a consistent `PYTHON_LIBRARIES` value.

## Result Variables

This module defines the following variables:

`PythonLibs_FOUND`

  Boolean indicating whether the (requested version of) Python libraries have been found. For backward compatibility, the `PYTHONLIBS_FOUND` variable is also set to the same value.

`PYTHONLIBS_VERSION_STRING`

  The version of the Python libraries found.

`PYTHON_LIBRARIES`

  Libraries needed to link against to use Python.

`PYTHON_INCLUDE_DIRS`

  Include directories needed to use Python.

## Cache Variables

The following cache variables may also be set to specify the Python installation to use:

`PYTHON_LIBRARY`

  The path to the Python library.

`PYTHON_INCLUDE_DIR`

  The directory containing the `Python.h` header file.

## Hints

This module accepts the following variables before calling `find_package(PythonLibs)`:

`Python_ADDITIONAL_VERSIONS`

  This variable can be used to specify a list of version numbers that should be taken into account when searching for Python.

## Deprecated Variables

These variables are provided for backward compatibility:

`PYTHON_DEBUG_LIBRARIES`

  Deprecated since version 2.8.8: Use `PYTHON_LIBRARIES` instead.

  Result variable that holds the path to the debug library.

`PYTHON_INCLUDE_PATH`

  Deprecated since version 2.8.0: Use `PYTHON_INCLUDE_DIR` or `PYTHON_INCLUDE_DIRS` instead.

  Result variable that holds the path to the directory containing the `Python.h` header file.

## Examples

In earlier versions of CMake, Python libraries were found and used in a project like this:

    find_package(PythonLibs)
    target_link_libraries(app PRIVATE ${PYTHON_LIBRARIES})
    target_include_directories(app PRIVATE ${PYTHON_INCLUDE_DIRS})

Starting with CMake 3.12, Python libraries can be found using the `FindPython` module. The equivalent example using the modern approach with an imported target is:

    find_package(Python COMPONENTS Development)
    target_link_libraries(app PRIVATE Python::Python)