DunePythonFindPackage
---------------------

Helpers for checking whether Python packages are available for a given
interpreter.

.. cmake:command:: dune_python_find_package

  Check whether a Python package can be imported and optionally whether it
  satisfies a version constraint.

  .. code-block:: cmake

    dune_python_find_package(
      PACKAGE <package>
      [RESULT <var>]
      [REQUIRED]
      [VERSION <version>]
      [EXACT]
      [INTERPRETER <python>]
    )

  ``PACKAGE``
    Name of the Python package to look for.

  ``RESULT``
    Variable that receives the result in the calling scope. If omitted, the
    default is ``DUNE_PYTHON_<package>_FOUND``. The package name is case
    sensitive and is typically lowercase.

  ``REQUIRED``
    If given, configuration fails when the package cannot be found.

  ``VERSION``
    Minimum version required for the package.

  ``EXACT``
    Require the version given by ``VERSION`` to match exactly.

  ``INTERPRETER``
    Python interpreter whose search path is used. The default is
    ``Python3::Interpreter``. This can differ from the system interpreter when
    using DUNE's configure-time virtual environment.

  The package check is performed by importing the module with the selected
  interpreter. If the import succeeds, the package version is queried through
  the dune-common helper script ``pyversion.py``.