# 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.

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:

    find_package(PythonLibs [<version>] [...])

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`

  Added in version 3.3.

  Boolean indicating whether the (requested version of) Python libraries were found.

`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

The following variables are provided for backward compatibility:

`PYTHONLIBS_FOUND`

  Deprecated since version 3.12: Use `PythonLibs_FOUND`, which has the same value.

  Boolean indicating whether the (requested version of) Python libraries were found.

`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)