FindPythonInterp

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 interpreter and determines the location of its executable.

Note

When using both this and the FindPythonLibs 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.

Note

A call to find_package(PythonInterp ${V}) for Python version V may find a python executable with no version suffix. In this case no attempt is made to avoid Python executables from other versions. Use FindPython3, FindPython2, or FindPython instead.

Result Variables

This module defines the following variables:

PythonInterp_FOUND

Boolean indicating whether the (requested version of) Python executable is found. For backward compatibility, the PYTHONINTERP_FOUND variable is also set to the same value.

PYTHON_VERSION_STRING

Python version found (e.g., 2.5.2).

PYTHON_VERSION_MAJOR

Python major version found (e.g., 2).

PYTHON_VERSION_MINOR

Python minor version found (e.g., 5).

PYTHON_VERSION_PATCH

Python patch version found (e.g., 2).

Cache Variables

The following cache variables may also be set:

PYTHON_EXECUTABLE

The path to the Python interpreter.

Hints

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

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.

Examples

Finding the Python interpreter in earlier versions of CMake:

find_package(PythonInterp)
execute_process(COMMAND ${PYTHON_EXECUTABLE} --help)

Starting with CMake 3.12, the Python interpreter can be found using the FindPython module. The equivalent example using the modern approach is:

find_package(Python)
execute_process(COMMAND ${Python_EXECUTABLE} --help)