Added in version 3.12.
Find Python 3 interpreter, compiler and development environment (include directories and libraries).
Added in version 3.19: When a version is requested, it can be specified as a simple value or as a
range. For a detailed description of version range usage and capabilities,
refer to the find_package() command.
The following 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).
Added in version 3.18: This component includes two sub-components which can be specified independently:
Development.Module: search for artifacts for Python 3 module
developments.
Development.Embed: search for artifacts for Python 3 embedding
developments.
Added in version 3.26:
Development.SABIModule: search for artifacts for Python 3 module
developments using the
Stable Application Binary Interface.
This component is available only for version 3.2 and upper.
NumPy: search for NumPy include directories.
Added in version 3.14: Added the NumPy component.
If no COMPONENTS are specified, Interpreter is assumed.
If component Development is specified, it implies sub-components
Development.Module and Development.Embed.
To ensure consistent versions between components Interpreter, Compiler,
Development (or one of its sub-components) 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 (or one of its
sub-components) are both specified, this module search only for interpreter
with same platform architecture as the one defined by CMake
configuration. This constraint does not apply if only Interpreter
component is specified.
This module defines the following Imported Targets:
Changed in version 3.14: Imported Targets are only created when
CMAKE_ROLE is PROJECT.
Python3::InterpreterPython 3 interpreter. This target is defined only if the Interpreter
component is found.
Python3::InterpreterDebugAdded in version 3.30.
Python 3 debug interpreter. This target is defined only if the
Interpreter component is found and the Python3_EXECUTABLE_DEBUG
variable is defined. The target is only defined on the Windows platform.
Python3::InterpreterMultiConfigAdded in version 3.30.
Python 3 interpreter. The release or debug version of the interpreter will be
used, based on the context (platform, configuration).
This target is defined only if the Interpreter component is found
Python3::CompilerPython 3 compiler. This target is defined only if the Compiler component
is found.
Python3::ModuleAdded in version 3.15.
Python 3 library for Python module. Target defined if component
Development.Module is found.
Python3::SABIModuleAdded in version 3.26.
Python 3 library for Python module using the Stable Application Binary
Interface. Target defined if component Development.SABIModule is found.
Python3::PythonPython 3 library for Python embedding. Target defined if component
Development.Embed is found.
Python3::NumPyAdded in version 3.14.
NumPy library for Python 3. Target defined if component NumPy is found.
This module will set the following variables in your project (see Standard Variable Names):
Python3_FOUNDSystem has the Python 3 requested components.
Python3_Interpreter_FOUNDSystem has the Python 3 interpreter.
Python3_EXECUTABLEPath to the Python 3 interpreter.
Python3_EXECUTABLE_DEBUGAdded in version 3.30.
Path to the debug Python 3 interpreter. It is only defined on Windows
platform.
Python3_INTERPRETERAdded in version 3.30.
Path to the Python 3 interpreter, defined as a
generator expression selecting
the Python3_EXECUTABLE or Python3_EXECUTABLE_DEBUG variable based on
the context (platform, configuration).
Python3_INTERPRETER_IDPython
ActivePython
Anaconda
Canopy
IronPython
PyPy
Python3_STDLIBStandard platform independent installation directory.
Information returned by sysconfig.get_path('stdlib').
Python3_STDARCHStandard platform dependent installation directory.
Information returned by sysconfig.get_path('platstdlib').
Python3_SITELIBThird-party platform independent installation directory.
Information returned by sysconfig.get_path('purelib').
Python3_SITEARCHThird-party platform dependent installation directory.
Information returned by sysconfig.get_path('platlib').
Python3_SOABIAdded in version 3.17.
Extension suffix for modules.
Information computed from sysconfig.get_config_var('EXT_SUFFIX') or
sysconfig.get_config_var('SOABI') or
python3-config --extension-suffix.
Python3_SOSABIAdded in version 3.26.
Extension suffix for modules using the Stable Application Binary Interface.
Information computed from importlib.machinery.EXTENSION_SUFFIXES if the
COMPONENT Interpreter was specified. Otherwise, the extension is abi3
except for Windows, MSYS and CYGWIN for which this is an empty
string.
Python3_Compiler_FOUNDSystem has the Python 3 compiler.
Python3_COMPILERPath to the Python 3 compiler. Only offered by IronPython.
Python3_COMPILER_IDIronPython
Python3_DOTNET_LAUNCHERAdded in version 3.18.
The .Net interpreter. Only used by IronPython implementation.
Python3_Development_FOUND
System has the Python 3 development artifacts.
Python3_Development.Module_FOUNDAdded in version 3.18.
System has the Python 3 development artifacts for Python module.
Python3_Development.SABIModule_FOUNDAdded in version 3.26.
System has the Python 3 development artifacts for Python module using the Stable Application Binary Interface.
Python3_Development.Embed_FOUNDAdded in version 3.18.
System has the Python 3 development artifacts for Python embedding.
Python3_INCLUDE_DIRS
The Python 3 include directories.
Python3_DEFINITIONSAdded in version 3.30.3.
The Python 3 preprocessor definitions.
Python3_DEBUG_POSTFIXAdded in version 3.30.
Postfix of debug python module. This variable can be used to define the
DEBUG_POSTFIX target property.
Python3_LINK_OPTIONSAdded in version 3.19.
The Python 3 link options. Some configurations require specific link options for a correct build and execution.
Python3_LIBRARIESThe Python 3 libraries.
Python3_LIBRARY_DIRSThe Python 3 library directories.
Python3_RUNTIME_LIBRARY_DIRSThe Python 3 runtime library directories.
Python3_SABI_LIBRARIESAdded in version 3.26.
The Python 3 libraries for the Stable Application Binary Interface.
Python3_SABI_LIBRARY_DIRSAdded in version 3.26.
The Python 3 SABI library directories.
Python3_RUNTIME_SABI_LIBRARY_DIRSAdded in version 3.26.
The Python 3 runtime SABI library directories.
Python3_VERSIONPython 3 version.
Python3_VERSION_MAJORPython 3 major version.
Python3_VERSION_MINORPython 3 minor version.
Python3_VERSION_PATCHPython 3 patch version.
Python3_PyPy_VERSIONAdded in version 3.18.
Python 3 PyPy version.
Python3_NumPy_FOUNDAdded in version 3.14.
System has the NumPy.
Python3_NumPy_INCLUDE_DIRSAdded in version 3.14.
The NumPy include directories.
Python3_NumPy_VERSIONAdded in version 3.14.
The NumPy version.
Python3_ROOT_DIRDefine the root directory of a Python 3 installation.
Python3_USE_STATIC_LIBSIf 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.
Note
This hint will be ignored on Windows because static libraries are not
available on this platform.
Python3_FIND_ABIAdded in version 3.16.
This variable defines which ABIs, as defined in PEP 3149, should be searched.
The Python3_FIND_ABI variable is a 4-tuple specifying, in that order,
pydebug (d), pymalloc (m), unicode (u) and
gil_disabled (t) flags.
Added in version 3.30: A fourth element, specifying the gil_disabled flag (i.e. free
threaded python), is added and is optional. If not specified, the value is
OFF.
Each element can be set to one of the following:
ON: Corresponding flag is selected.
OFF: Corresponding flag is not selected.
ANY: The two possibilities (ON and OFF) will be searched.
Note
If Python3_FIND_ABI is not defined, any ABI, excluding the
gil_disabled flag, will be searched.
From this 4-tuple, various ABIs will be searched starting from the most
specialized to the most general. Moreover, when ANY is specified for
pydebug and gil_disabled, debug and free threaded versions
will be searched after non-debug and non-gil-disabled ones.
For example, if we have:
set (Python3_FIND_ABI "ON" "ANY" "ANY" "ON")
The following flags combinations will be appended, in that order, to the
artifact names: tdmu, tdm, tdu, and td.
And to search any possible ABIs:
set (Python3_FIND_ABI "ANY" "ANY" "ANY" "ANY")
The following combinations, in that order, will be used: mu, m,
u, <empty>, dmu, dm, du, d, tmu, tm, tu,
t, tdmu, tdm, tdu, and td.
Note
This hint is useful only on POSIX systems except for the
gil_disabled flag. So, on Windows systems,
when Python_FIND_ABI is defined, Python distributions from
python.org will be found only if the value for
each flag is OFF or ANY except for the fourth one
(gil_disabled).
Python3_FIND_STRATEGYAdded in version 3.15.
This variable defines how lookup will be done.
The Python3_FIND_STRATEGY variable can be set to one of the following:
VERSION: Try to find the most recent version in all specified
locations.
This is the default if policy CMP0094 is undefined or set to
OLD.
LOCATION: Stops lookup as soon as a version satisfying version
constraints is founded.
This is the default if policy CMP0094 is set to NEW.
See also Python3_FIND_UNVERSIONED_NAMES.
Python3_FIND_REGISTRYAdded in version 3.13.
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 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.
Python3_FIND_FRAMEWORKAdded in version 3.15.
On macOS the Python3_FIND_FRAMEWORK variable determine the order of
preference between Apple-style and unix-style package components.
This variable can take same values as CMAKE_FIND_FRAMEWORK
variable.
Note
Value ONLY is not supported so FIRST will be used instead.
If Python3_FIND_FRAMEWORK is not defined, CMAKE_FIND_FRAMEWORK
variable will be used, if any.
Python3_FIND_VIRTUALENVAdded in version 3.15.
This variable defines the handling of virtual environments managed by
virtualenv or conda. It is meaningful only when a virtual environment
is active (i.e. the activate script has been evaluated). In this case, it
takes precedence over Python3_FIND_REGISTRY and CMAKE_FIND_FRAMEWORK
variables. The Python3_FIND_VIRTUALENV variable can be set to 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 but environment variable PATH is always considered.
In this case, variable Python3_FIND_REGISTRY (Windows) or
CMAKE_FIND_FRAMEWORK (macOS) can be set with value LAST or
NEVER to select preferably the interpreter from the virtual
environment.
Added in version 3.17: Added support for conda environments.
Note
If the component Development is requested (or one of its
sub-components) and is not found or the wrong artifacts are returned,
including also the component Interpreter may be helpful.
Python3_FIND_IMPLEMENTATIONSAdded in version 3.18.
This variable defines, in an ordered list, the different implementations
which will be searched. The Python3_FIND_IMPLEMENTATIONS variable can
hold the following values:
CPython: this is the standard implementation. Various products, like
Anaconda or ActivePython, rely on this implementation.
IronPython: This implementation use the CSharp language for
.NET Framework on top of the Dynamic Language Runtime (DLR).
See IronPython.
PyPy: This implementation use RPython language and
RPython translation toolchain to produce the python interpreter.
See PyPy.
The default value is:
Windows platform: CPython, IronPython
Other platforms: CPython
Note
This hint has the lowest priority of all hints, so even if, for example,
you specify IronPython first and CPython in second, a python
product based on CPython can be selected because, for example with
Python3_FIND_STRATEGY=LOCATION, each location will be search first for
IronPython and second for CPython.
Note
When IronPython is specified, on platforms other than Windows, the
.Net interpreter (i.e. mono command) is expected to be available
through the PATH variable.
Python3_FIND_UNVERSIONED_NAMESAdded in version 3.20.
This variable defines how the generic names will be searched. Currently, it
only applies to the generic names of the interpreter, namely, python3 and
python.
The Python3_FIND_UNVERSIONED_NAMES variable can be set to one of the
following values:
FIRST: The generic names are searched before the more specialized ones
(such as python3.5 for example).
LAST: The generic names are searched after the more specialized ones.
This is the default.
NEVER: The generic name are not searched at all.
See also Python3_FIND_STRATEGY.
Added in version 3.16.
To solve special cases, it is possible to specify directly the artifacts by setting the following variables:
Python3_EXECUTABLEThe path to the interpreter.
Python3_COMPILERThe path to the compiler.
Python3_DOTNET_LAUNCHERAdded in version 3.18.
The .Net interpreter. Only used by IronPython implementation.
Python3_LIBRARYThe path to the library. It will be used to compute the
variables Python3_LIBRARIES, Python3_LIBRARY_DIRS and
Python3_RUNTIME_LIBRARY_DIRS.
Python3_SABI_LIBRARYAdded in version 3.26.
The path to the library for Stable Application Binary Interface. It will be
used to compute the variables Python3_SABI_LIBRARIES,
Python3_SABI_LIBRARY_DIRS and Python3_RUNTIME_SABI_LIBRARY_DIRS.
Python3_INCLUDE_DIRThe path to the directory of the Python headers. It will be used to
compute the variable Python3_INCLUDE_DIRS.
Python3_NumPy_INCLUDE_DIRThe path to the directory of the NumPy headers. It will be used to
compute the variable Python3_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 responsibility to ensure the consistency of the various artifacts.
By default, this module supports multiple calls in different directories of a project with different version/component requirements while providing correct and consistent results for each call. To support this behavior, CMake cache is not used in the traditional way which can be problematic for interactive specification. So, to enable also interactive specification, module behavior can be controlled with the following variable:
Python3_ARTIFACTS_INTERACTIVEAdded in version 3.18.
Selects the behavior of the module. This is a boolean variable:
If set to TRUE: Create CMake cache entries for the above artifact
specification variables so that users can edit them interactively.
This disables support for multiple version/component requirements.
If set to FALSE or undefined: Enable multiple version/component
requirements.
Python3_ARTIFACTS_PREFIXAdded in version 4.0.
Define a custom prefix which will be used for the definition of all the result variables, targets, and commands. By using this variable, this module supports multiple calls in the same directory with different version/component requirements. For example, in case of cross-compilation, development components are needed but the native python interpreter can also be required:
find_package(Python3 COMPONENTS Development)
set(Python3_ARTIFACTS_PREFIX "_HOST")
find_package(Python3 COMPONENTS Interpreter)
# Here Python3_HOST_EXECUTABLE and Python3_HOST::Interpreter artifacts are defined
Note
For consistency with standard behavior of modules, the various standard
_FOUND variables (i.e. without the custom prefix) are also defined by
each call to the find_package() command.
This module defines the command Python3_add_library (when
CMAKE_ROLE is PROJECT), which has the same semantics as
add_library() and adds a dependency to target Python3::Python or,
when library type is MODULE, to target Python3::Module or
Python3::SABIModule (when USE_SABI option is specified) and takes care
of Python module naming rules:
Python3_add_library (<name> [STATIC | SHARED | MODULE [USE_SABI <version>] [WITH_SOABI]]
<source1> [<source2> ...])
If the library type is not specified, MODULE is assumed.
Added in version 3.17: For MODULE library type, if option WITH_SOABI is specified, the
module suffix will include the Python3_SOABI value, if any.
Added in version 3.26: For MODULE type, if the option USE_SABI is specified, the
preprocessor definition Py_LIMITED_API will be specified, as PRIVATE,
for the target <name> with the value computed from <version> argument.
The expected format for <version> is major[.minor], where each
component is a numeric value. If minor component is specified, the
version should be, at least, 3.2 which is the version where the
Stable Application Binary Interface
was introduced. Specifying only major version 3 is equivalent to 3.2.
When option WITH_SOABI is also specified, the module suffix will include
the Python3_SOSABI value, if any.
Added in version 3.30: For MODULE type, the DEBUG_POSTFIX target property is
initialized with the value of Python3_DEBUG_POSTFIX variable if defined.