Update cherrypy==18.9.0

lib/pydantic/plugin/_loader.py

@@ -0,0 +1,50 @@
+from __future__ import annotations
+
+import importlib.metadata as importlib_metadata
+import warnings
+from typing import TYPE_CHECKING, Final, Iterable
+
+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()