FindPython¶
Find Python interpreter, compiler and development environment (include directories and libraries).
The following components are supported:
Interpreter: search for Python interpreter.Compiler: search for Python compiler. Only offered by IronPython.Development: search for development artifacts (include directories and libraries).NumPy: search for NumPy include directories.
If no COMPONENTS are specified, Interpreter is assumed.
To ensure consistent versions between components Interpreter, Compiler,
Development and NumPy, specify all components at the same time:
find_package (Python COMPONENTS Interpreter Development)
This module looks preferably for version 3 of Python. If not found, version 2
is searched.
To manage concurrent versions 3 and 2 of Python, use FindPython3 and
FindPython2 modules rather than this one.
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):
Python::Interpreter- Python interpreter. Target defined if component
Interpreteris found. Python::Compiler- Python compiler. Target defined if component
Compileris found. Python::Python- Python library for Python embedding. Target defined if component
Developmentis found. Python::Module- Python library for Python module. Target defined if component
Developmentis found. Python::NumPy- NumPy Python library. Target defined if component
NumPyis found.
Result Variables¶
This module will set the following variables in your project (see Standard Variable Names):
Python_FOUND- System has the Python requested components.
Python_Interpreter_FOUND- System has the Python interpreter.
Python_EXECUTABLE- Path to the Python interpreter.
Python_INTERPRETER_ID- A short string unique to the interpreter. Possible values include:
- Python
- ActivePython
- Anaconda
- Canopy
- IronPython
Python_STDLIBStandard platform independent installation directory.
Information returned by
distutils.sysconfig.get_python_lib(plat_specific=False,standard_lib=True).Python_STDARCHStandard platform dependent installation directory.
Information returned by
distutils.sysconfig.get_python_lib(plat_specific=True,standard_lib=True).Python_SITELIBThird-party platform independent installation directory.
Information returned by
distutils.sysconfig.get_python_lib(plat_specific=False,standard_lib=False).Python_SITEARCHThird-party platform dependent installation directory.
Information returned by
distutils.sysconfig.get_python_lib(plat_specific=True,standard_lib=False).Python_Compiler_FOUND- System has the Python compiler.
Python_COMPILER- Path to the Python compiler. Only offered by IronPython.
Python_COMPILER_ID- A short string unique to the compiler. Possible values include:
- IronPython
Python_Development_FOUND- System has the Python development artifacts.
Python_INCLUDE_DIRS- The Python include directories.
Python_LIBRARIES- The Python libraries.
Python_LIBRARY_DIRS- The Python library directories.
Python_RUNTIME_LIBRARY_DIRS- The Python runtime library directories.
Python_VERSION- Python version.
Python_VERSION_MAJOR- Python major version.
Python_VERSION_MINOR- Python minor version.
Python_VERSION_PATCH- Python patch version.
Python_NumPy_FOUND- System has the NumPy.
Python_NumPy_INCLUDE_DIRS- The NumPy include directries.
Python_NumPy_VERSION- The NumPy version.
Hints¶
Python_ROOT_DIR- Define the root directory of a Python installation.
Python_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.
Python_FIND_ABIThis variable defines which ABIs, as defined in PEP 3149, should be searched.
Note
This hint will be honored only when searched for
Pythonversion 3.Note
If
Python_FIND_ABIis not defined, any ABI will be searched.The
Python_FIND_ABIvariable is a 3-tuple specifying, in that order,pydebug(d),pymalloc(m) andunicode(u) flags. Each element can be set to one of the following:ON: Corresponding flag is selected.OFF: Corresponding flag is not selected.ANY: The two posibilties (ONandOFF) will be searched.
From this 3-tuple, various ABIs will be searched starting from the most specialized to the most general. Moreover,
debugversions will be searched afternon-debugones.For example, if we have:
set (Python_FIND_ABI "ON" "ANY" "ANY")
The following flags combinations will be appended, in that order, to the artifact names:
dmu,dm,du, andd.And to search any possible ABIs:
set (Python_FIND_ABI "ANY" "ANY" "ANY")
The following combinations, in that order, will be used:
mu,m,u,<empty>,dmu,dm,duandd.Note
This hint is useful only on
POSIXsystems. So, onWindowssystems, whenPython_FIND_ABIis defined,Pythondistributions from python.org will be found only if value for each flag isOFForANY.Python_FIND_STRATEGYThis variable defines how lookup will be done. The
Python_FIND_STRATEGYvariable can be set to empty or one of the following:Python_FIND_REGISTRYOn Windows the
Python_FIND_REGISTRYvariable determine the order of preference between registry and environment variables. thePython_FIND_REGISTRYvariable 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.
Python_FIND_FRAMEWORKOn macOS the
Python_FIND_FRAMEWORKvariable determine the order of preference between Apple-style and unix-style package components. This variable can be set to empty or take same values asCMAKE_FIND_FRAMEWORKvariable.Note
Value
ONLYis not supported soFIRSTwill be used instead.If
Python_FIND_FRAMEWORKis not defined,CMAKE_FIND_FRAMEWORKvariable will be used, if any.Python_FIND_VIRTUALENVThis variable defines the handling of virtual environments. It is meaningfull only when a virtual environment is active (i.e. the
activatescript has been evaluated). In this case, it takes precedence overPython_FIND_REGISTRYandCMAKE_FIND_FRAMEWORKvariables. ThePython_FIND_VIRTUALENVvariable can be set to empty or one of the following:FIRST: The virtual environment is used before any other standard paths to look-up for the interpreter. This is the default.ONLY: Only the virtual environment is used to look-up for the interpreter.STANDARD: The virtual environment is not used to look-up for the interpreter. In this case, variablePython_FIND_REGISTRY(Windows) orCMAKE_FIND_FRAMEWORK(macOS) can be set with valueLASTorNEVERto select preferably the interpreter from the virtual environment.
Note
If the component
Developmentis requested, it is strongly recommended to also include the componentInterpreterto get expected result.
Artifacts Specification¶
To solve special cases, it is possible to specify directly the artifacts by setting the following variables:
Python_EXECUTABLE- The path to the interpreter.
Python_COMPILER- The path to the compiler.
Python_LIBRARY- The path to the library. It will be used to compute the
variables
Python_LIBRARIES,Python_LIBRAY_DIRSandPython_RUNTIME_LIBRARY_DIRS. Python_INCLUDE_DIR- The path to the directory of the
Pythonheaders. It will be used to compute the variablePython_INCLUDE_DIRS. Python_NumPy_INCLUDE_DIR- The path to the directory of the
NumPyheaders. It will be used to compute the variablePython_NumPy_INCLUDE_DIRS.
Note
All paths must be absolute. Any artifact specified with a relative path will be ignored.
Note
When an artifact is specified, all HINTS will be ignored and no search
will be performed for this artifact.
If more than one artifact is specified, it is the user’s responsability to ensure the consistency of the various artifacts.
Commands¶
This module defines the command Python_add_library (when
CMAKE_ROLE is PROJECT), which has the same semantics as
add_library() and adds a dependency to target Python::Python or,
when library type is MODULE, to target Python::Module and takes care of
Python module naming rules:
Python_add_library (my_module MODULE src1.cpp)
If library type is not specified, MODULE is assumed.