FindPython3

Find Python 3 interpreter, compiler and development environment (include directories and libraries).

Three components are supported:

  • Interpreter: search for Python 3 interpreter
  • Compiler: search for Python 3 compiler. Only offered by IronPython.
  • Development: search for development artifacts (include directories and libraries)
  • NumPy: search for NumPy include directories.

If no COMPONENTS is specified, Interpreter is assumed.

To ensure consistent versions between components Interpreter, Compiler, Development and NumPy, specify all components at the same time:

find_package (Python3 COMPONENTS Interpreter Development)

This module looks only for version 3 of Python. This module can be used concurrently with FindPython2 module to use both Python versions.

The FindPython module can be used if Python version does not matter for you.

Note

If components Interpreter and Development are both specified, this module search only for interpreter with same platform architecture as the one defined by CMake configuration. This contraint does not apply if only Interpreter component is specified.

Imported Targets

This module defines the following Imported Targets (when CMAKE_ROLE is PROJECT):

Python3::Interpreter
Python 3 interpreter. Target defined if component Interpreter is found.
Python3::Compiler
Python 3 compiler. Target defined if component Compiler is found.
Python3::Python
Python 3 library. Target defined if component Development is found.
Python3::NumPy
NumPy library for Python 3. Target defined if component NumPy is found.

Result Variables

This module will set the following variables in your project (see Standard Variable Names):

Python3_FOUND
System has the Python 3 requested components.
Python3_Interpreter_FOUND
System has the Python 3 interpreter.
Python3_EXECUTABLE
Path to the Python 3 interpreter.
Python3_INTERPRETER_ID
A short string unique to the interpreter. Possible values include:
  • Python
  • ActivePython
  • Anaconda
  • Canopy
  • IronPython
Python3_STDLIB

Standard platform independent installation directory.

Information returned by distutils.sysconfig.get_python_lib(plat_specific=False,standard_lib=True).

Python3_STDARCH

Standard platform dependent installation directory.

Information returned by distutils.sysconfig.get_python_lib(plat_specific=True,standard_lib=True).

Python3_SITELIB

Third-party platform independent installation directory.

Information returned by distutils.sysconfig.get_python_lib(plat_specific=False,standard_lib=False).

Python3_SITEARCH

Third-party platform dependent installation directory.

Information returned by distutils.sysconfig.get_python_lib(plat_specific=True,standard_lib=False).

Python3_Compiler_FOUND
System has the Python 3 compiler.
Python3_COMPILER
Path to the Python 3 compiler. Only offered by IronPython.
Python3_COMPILER_ID
A short string unique to the compiler. Possible values include:
  • IronPython
Python3_Development_FOUND
System has the Python 3 development artifacts.
Python3_INCLUDE_DIRS
The Python 3 include directories.
Python3_LIBRARIES
The Python 3 libraries.
Python3_LIBRARY_DIRS
The Python 3 library directories.
Python3_RUNTIME_LIBRARY_DIRS
The Python 3 runtime library directories.
Python3_VERSION
Python 3 version.
Python3_VERSION_MAJOR
Python 3 major version.
Python3_VERSION_MINOR
Python 3 minor version.
Python3_VERSION_PATCH
Python 3 patch version.
Python3_NumPy_FOUND
System has the NumPy.
Python3_NumPy_INCLUDE_DIRS
The NumPy include directries.
Python3_NumPy_VERSION
The NumPy version.

Hints

Python3_ROOT_DIR
Define the root directory of a Python 3 installation.
Python3_USE_STATIC_LIBS
  • If not defined, search for shared libraries and static libraries in that order.
  • If set to TRUE, search only for static libraries.
  • If set to FALSE, search only for shared libraries.
Python3_FIND_REGISTRY

On Windows the Python3_FIND_REGISTRY variable determine the order of preference between registry and environment variables. the Python3_FIND_REGISTRY variable can be set to empty or one of the following:

  • FIRST: Try to use registry before environment variables. This is the default.
  • LAST: Try to use registry after environment variables.
  • NEVER: Never try to use registry.
CMAKE_FIND_FRAMEWORK

On OS X the CMAKE_FIND_FRAMEWORK variable determine the order of preference between Apple-style and unix-style package components.

Note

Value ONLY is not supported so FIRST will be used instead.

Note

If a Python virtual environment is configured, set variable Python_FIND_REGISTRY (Windows) or CMAKE_FIND_FRAMEWORK (macOS) with value LAST or NEVER to select it preferably.

Commands

This module defines the command Python3_add_library (when CMAKE_ROLE is PROJECT), which has the same semantics as add_library(), but takes care of Python module naming rules (only applied if library is of type MODULE), and adds a dependency to target Python3::Python:

Python3_add_library (my_module MODULE src1.cpp)

If library type is not specified, MODULE is assumed.