from __future__ import annotations import sys import warnings from typing import TYPE_CHECKING, Iterable from typing_extensions import Final if sys.version_info >= (3, 8): import importlib.metadata as importlib_metadata else: import importlib_metadata if TYPE_CHECKING: from . import PydanticPluginProtocol PYDANTIC_ENTRY_POINT_GROUP: Final[str] = 'pydantic' # cache of plugins _plugins: dict[str, PydanticPluginProtocol] | None = None # return no plugins while loading plugins to avoid recursion and errors while import plugins # this means that if plugins use pydantic _loading_plugins: bool = False def get_plugins() -> Iterable[PydanticPluginProtocol]: """Load plugins for Pydantic. Inspired by: https://github.com/pytest-dev/pluggy/blob/1.3.0/src/pluggy/_manager.py#L376-L402 """ global _plugins, _loading_plugins if _loading_plugins: # this happens when plugins themselves use pydantic, we return no plugins return () elif _plugins is None: _plugins = {} # set _loading_plugins so any plugins that use pydantic don't themselves use plugins _loading_plugins = True try: for dist in importlib_metadata.distributions(): for entry_point in dist.entry_points: if entry_point.group != PYDANTIC_ENTRY_POINT_GROUP: continue if entry_point.value in _plugins: continue try: _plugins[entry_point.value] = entry_point.load() except (ImportError, AttributeError) as e: warnings.warn( f'{e.__class__.__name__} while loading the `{entry_point.name}` Pydantic plugin, ' f'this plugin will not be installed.\n\n{e!r}' ) finally: _loading_plugins = False return _plugins.values()