Fix type-hinting in base.py

Author: JonnyWong16

plexapi/base.py

@@ -1,5 +1,5 @@
 import re
-from typing import TYPE_CHECKING, Generic, Iterable, List, Optional, TypeVar, Union
+from typing import TYPE_CHECKING, Any, Callable, Generic, Iterable, List, Optional, TypeVar, Union, overload
 import weakref
 from functools import cached_property
 from urllib.parse import parse_qsl, urlencode, urlparse
@@ -12,11 +12,13 @@
 if TYPE_CHECKING:
     from plexapi.server import PlexServer
 
-PlexObjectT = TypeVar("PlexObjectT", bound='PlexObject')
-MediaContainerT = TypeVar("MediaContainerT", bound="MediaContainer")
+_T = TypeVar('_T')
 
-USER_DONT_RELOAD_FOR_KEYS = set()
-_DONT_RELOAD_FOR_KEYS = {'key', 'sourceURI'}
+PlexObjectT = TypeVar('PlexObjectT', bound='PlexObject')
+MediaContainerT = TypeVar('MediaContainerT', bound='MediaContainer')
+
+USER_DONT_RELOAD_FOR_KEYS: set[str] = set()
+_DONT_RELOAD_FOR_KEYS: set[str] = {'key', 'sourceURI'}
 OPERATORS = {
     'exact': lambda v, q: v == q,
     'iexact': lambda v, q: v.lower() == q.lower(),
@@ -38,15 +40,15 @@
 }
 
 
-class cached_data_property(cached_property):
+class cached_data_property(cached_property, Generic[_T]):
     """Caching for PlexObject data properties.
 
     This decorator creates properties that cache their values with
     automatic invalidation on data changes.
     """
 
-    def __new__(cls, *args, **kwargs) -> "cached_data_property":
-        return super().__new__(cls)
+    def __init__(self, func: Callable[[Any], _T]) -> None:
+        super().__init__(func)
 
     def __set_name__(self, owner, name):
         """Register the annotated property in the parent class's _cached_data_properties set."""
@@ -55,6 +57,17 @@ def __set_name__(self, owner, name):
             owner._cached_data_properties = set()
         owner._cached_data_properties.add(name)
 
+    @overload
+    def __get__(self, instance: None, owner: type | None = None) -> "cached_data_property[_T]":
+        ...
+
+    @overload
+    def __get__(self, instance: object, owner: type | None = None) -> _T:
+        ...
+
+    def __get__(self, instance: object | None, owner: type | None = None) -> "cached_data_property[_T] | _T":
+        return super().__get__(instance, owner)
+
 
 class PlexObjectMeta(type):
     """Metaclass for PlexObject to handle cached_data_properties."""
@@ -76,6 +89,11 @@ def __new__(mcs, name, bases, attrs):
         return super().__new__(mcs, name, bases, attrs)
 
 
+class MediaContainerMeta(PlexObjectMeta, type(List)):
+    """Metaclass for MediaContainer that combines PlexObjectMeta with Generic/List metaclass."""
+    pass
+
+
 class PlexObject(metaclass=PlexObjectMeta):
     """ Base class for all Plex objects.
 
@@ -1144,6 +1162,7 @@ class MediaContainer(
     Generic[PlexObjectT],
     List[PlexObjectT],
     PlexObject,
+    metaclass=PlexObjectMeta,
 ):
     """ Represents a single MediaContainer.