diff --git a/sphinx/domains/python/__init__.py b/sphinx/domains/python/__init__.py
index bc6099c2e..cac8e0176 100644
--- a/sphinx/domains/python/__init__.py
+++ b/sphinx/domains/python/__init__.py
@@ -714,12 +714,16 @@ class PythonDomain(Domain):
                                          synopsis, platform, deprecated)
 
     def clear_doc(self, docname: str) -> None:
-        for fullname, obj in list(self.objects.items()):
-            if obj.docname == docname:
-                del self.objects[fullname]
-        for modname, mod in list(self.modules.items()):
-            if mod.docname == docname:
-                del self.modules[modname]
+        to_remove = [
+            fullname for fullname, obj in self.objects.items() if obj.docname == docname
+        ]
+        for fullname in to_remove:
+            del self.objects[fullname]
+        to_remove = [
+            modname for modname, mod in self.modules.items() if mod.docname == docname
+        ]
+        for fullname in to_remove:
+            del self.modules[fullname]
 
     def merge_domaindata(self, docnames: Set[str], otherdata: dict[str, Any]) -> None:
         # XXX check duplicates?