gh-112509: Fix keys being present in both required_keys and optional_keys in TypedDict (#112512)

Co-authored-by: Alex Waygood <Alex.Waygood@Gmail.com>

1 files changed, 20 insertions, 5 deletions

diff --git a/Lib/typing.py b/Lib/typing.py
index 216f0c1..b3af701 100644
--- a/Lib/typing.py
+++ b/Lib/typing.py
@@ -2884,8 +2884,14 @@ class _TypedDictMeta(type):
 
         for base in bases:
             annotations.update(base.__dict__.get('__annotations__', {}))
-            required_keys.update(base.__dict__.get('__required_keys__', ()))
-            optional_keys.update(base.__dict__.get('__optional_keys__', ()))
+
+            base_required = base.__dict__.get('__required_keys__', set())
+            required_keys |= base_required
+            optional_keys -= base_required
+
+            base_optional = base.__dict__.get('__optional_keys__', set())
+            required_keys -= base_optional
+            optional_keys |= base_optional
 
         annotations.update(own_annotations)
         for annotation_key, annotation_type in own_annotations.items():
@@ -2897,14 +2903,23 @@ class _TypedDictMeta(type):
                     annotation_origin = get_origin(annotation_type)
 
             if annotation_origin is Required:
-                required_keys.add(annotation_key)
+                is_required = True
             elif annotation_origin is NotRequired:
-                optional_keys.add(annotation_key)
-            elif total:
+                is_required = False
+            else:
+                is_required = total
+
+            if is_required:
                 required_keys.add(annotation_key)
+                optional_keys.discard(annotation_key)
             else:
                 optional_keys.add(annotation_key)
+                required_keys.discard(annotation_key)
 
+        assert required_keys.isdisjoint(optional_keys), (
+            f"Required keys overlap with optional keys in {name}:"
+            f" {required_keys=}, {optional_keys=}"
+        )
         tp_dict.__annotations__ = annotations
         tp_dict.__required_keys__ = frozenset(required_keys)
         tp_dict.__optional_keys__ = frozenset(optional_keys)