BUG: Index._id (pandas-dev#37321)

Author: topper-123

pandas/core/indexes/base.py

@@ -220,7 +220,7 @@ def _outer_indexer(self, left, right):
 
     _typ = "index"
     _data: Union[ExtensionArray, np.ndarray]
-    _id: _Identity
+    _id: Optional[_Identity] = None
     _name: Label = None
     # MultiIndex.levels previously allowed setting the index name. We
     # don't allow this anymore, and raise if it happens rather than
@@ -541,10 +541,14 @@ def is_(self, other) -> bool:
         --------
         Index.identical : Works like ``Index.is_`` but also checks metadata.
         """
-        try:
-            return self._id is other._id
-        except AttributeError:
+        if self is other:
+            return True
+        elif not hasattr(other, "_id"):
             return False
+        elif com.any_none(self._id, other._id):
+            return False
+        else:
+            return self._id is other._id
 
     def _reset_identity(self) -> None:
         """