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How to use prefer_pure_python_imports method in refurb

Best Python code snippet using refurb_python

mypy_visitor.py

Source:mypy_visitor.py

...36import mypy.traverser37VisitorNodeTypeMap = dict[str, type[mypy.nodes.Node]]38Namespace = dict[str, Any]  # type: ignore39@contextmanager40def prefer_pure_python_imports() -> Iterator[None]:41    """42    During the scope of this context manager, all imports will be done using43    pure python versions when available.44    Credit to this answer on SO: https://stackoverflow.com/a/68685189/45    """46    @dataclass47    class PreferPureLoaderHook:48        orig_hook: Callable[[str], PathEntryFinder]49        def __call__(self, path: str) -> PathEntryFinder:50            finder = self.orig_hook(path)51            if isinstance(finder, FileFinder):52                # Move pure python file loaders to the front53                finder._loaders.sort(  # type: ignore54                    key=lambda pair: 0 if pair[0] in (".py", ".pyc") else 155                )56            return finder57    sys.path_hooks = [PreferPureLoaderHook(h) for h in sys.path_hooks]58    sys.path_importer_cache.clear()59    yield60    # Restore the previous behaviour61    original_hooks = []62    for hook in sys.path_hooks:63        assert isinstance(hook, PreferPureLoaderHook)64        original_hooks.append(hook.orig_hook)65    sys.path_hooks = original_hooks66    sys.path_importer_cache.clear()67@contextmanager68def pure_python_mypy() -> Iterator[None]:69    """70    Inside this context, all mypy related imports are done with the pure python71    versions.72    Any existing mypy module that was imported before needs to be reimported73    before use within the context.74    Upon exiting, the previous implementations are restored.75    """76    def loaded_mypy_modules() -> Iterator[str]:77        """Covenient block to get names of imported mypy modules"""78        for mod_name in sys.modules:79            if mod_name == "mypy" or mod_name.startswith("mypy."):80                yield mod_name81    # First, backup all imported mypy modules and remove them from sys.modules,82    # so they will not be found in resolution83    saved_mypy = {}84    for mod_name in list(loaded_mypy_modules()):85        saved_mypy[mod_name] = sys.modules.pop(mod_name)86    with prefer_pure_python_imports():87        # After the modules are clean, ensure the newly imported mypy modules88        # are their pure python versions.89        # - Pure python: methods are FunctionType90        # - Native: methods are MethodDescriptorType91        from mypy.traverser import TraverserVisitor92        assert isinstance(93            typing.cast(FunctionType, TraverserVisitor.visit_var), FunctionType94        )95        # Give back control96        yield97    # We're back and this is where we do cleanup. We'll remove all imported98    # mypy modules (pure python) and restore the previously backed-up ones99    # (allegedly native implementations)100    for mod_name in list(loaded_mypy_modules()):...

pure_importer.py

Source:pure_importer.py

...13            # Move pure python file loaders to the front14            finder._loaders.sort(key=lambda pair: 0 if pair[0] in (".py", ".pyc") else 1)  # type: ignore15        return finder16@contextmanager17def prefer_pure_python_imports():18    sys.path_hooks = [PreferPureLoaderHook(h) for h in sys.path_hooks]19    sys.path_importer_cache.clear()20    yield21    assert all(isinstance(h, PreferPureLoaderHook) for h in sys.path_hooks)22    sys.path_hooks = [h.orig_hook for h in sys.path_hooks]...

pure_importer_test.py

Source:pure_importer_test.py

...15        sys.modules.update(saved)16@pytest.mark.skipif(17    sys.version_info >= (3, 10), reason="no compiled pydantic on 3.10 (yet)"18)19def test_prefer_pure_python_imports():20    pydantic = importlib.import_module("pydantic")21    assert pydantic.compiled22    with _pydantic_unloaded():23        with prefer_pure_python_imports():24            pydantic = importlib.import_module("pydantic")...

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