Method test_module_importability

tests/cloudpickle_test.py:767–826

(self)

        assert b"math" not in b

    def test_module_importability(self):
        import pickle
        import os.path
        import collections
        import collections.abc

        assert _should_pickle_by_reference(pickle)
        assert _should_pickle_by_reference(os.path)  # fake (aliased) module
        assert _should_pickle_by_reference(collections)  # package
        assert _should_pickle_by_reference(collections.abc)  # module in package

        dynamic_module = types.ModuleType("dynamic_module")
        assert not _should_pickle_by_reference(dynamic_module)

        if platform.python_implementation() == "PyPy":
            import _codecs

            assert _should_pickle_by_reference(_codecs)

        # #354: Check that modules created dynamically during the import of
        # their parent modules are considered importable by cloudpickle.
        # See the mod_with_dynamic_submodule documentation for more
        # details of this use case.
        m = pytest.importorskip(
            "_cloudpickle_testpkg.mod.dynamic_submodule"
        )  # noqa F841
        assert _should_pickle_by_reference(m)
        assert pickle_depickle(m, protocol=self.protocol) is m

        # Check for similar behavior for a module that cannot be imported by
        # attribute lookup.
        from _cloudpickle_testpkg.mod import dynamic_submodule_two as m2

        assert _should_pickle_by_reference(m2)
        assert pickle_depickle(m2, protocol=self.protocol) is m2

        # Submodule_three is a dynamic module only importable via module lookup
        with pytest.raises(ImportError):
            import _cloudpickle_testpkg.mod.submodule_three  # noqa
        from _cloudpickle_testpkg.mod import submodule_three as m3

        assert not _should_pickle_by_reference(m3)

        # This module cannot be pickled using attribute lookup (as it does not
        # have a `__module__` attribute like classes and functions.
        assert not hasattr(m3, "__module__")
        depickled_m3 = pickle_depickle(m3, protocol=self.protocol)
        assert depickled_m3 is not m3
        assert m3.f(1) == depickled_m3.f(1)

        # Do the same for an importable dynamic submodule inside a dynamic
        # module inside a file-backed module.
        import _cloudpickle_testpkg.mod.dynamic_submodule.dynamic_subsubmodule as sm  # noqa

        assert _should_pickle_by_reference(sm)
        assert pickle_depickle(sm, protocol=self.protocol) is sm

        expected = "cannot check importability of object instances"