def load_env_plugins()

in gym/envs/registration.py [0:0]

• 35 lines of code
• 14 McCabe index (conditional complexity)

def load_env_plugins(entry_point: str = "gym.envs") -> None:
    # Load third-party environments
    for plugin in metadata.entry_points(group=entry_point):
        # Python 3.8 doesn't support plugin.module, plugin.attr
        # So we'll have to try and parse this ourselves
        module, attr = None, None
        try:
            module, attr = plugin.module, plugin.attr  # type: ignore  ## error: Cannot access member "attr" for type "EntryPoint"
        except AttributeError:
            if ":" in plugin.value:
                module, attr = plugin.value.split(":", maxsplit=1)
            else:
                module, attr = plugin.value, None
        except Exception as e:
            warnings.warn(
                f"While trying to load plugin `{plugin}` from {entry_point}, an exception occurred: {e}"
            )
            module, attr = None, None
        finally:
            if attr is None:
                raise error.Error(
                    f"Gym environment plugin `{module}` must specify a function to execute, not a root module"
                )

        context = namespace(plugin.name)
        if plugin.name.startswith("__") and plugin.name.endswith("__"):
            # `__internal__` is an artifact of the plugin system when
            # the root namespace had an allow-list. The allow-list is now
            # removed and plugins can register environments in the root
            # namespace with the `__root__` magic key.
            if plugin.name == "__root__" or plugin.name == "__internal__":
                context = contextlib.nullcontext()
            else:
                logger.warn(
                    f"The environment namespace magic key `{plugin.name}` is unsupported. "
                    "To register an environment at the root namespace you should specify the `__root__` namespace."
                )

        with context:
            fn = plugin.load()
            try:
                fn()
            except Exception as e:
                logger.warn(str(e))