Fix integer check; also add column with integer name in test case.

pandas/core/generic.py

@@ -461,7 +461,7 @@ def _get_index_resolvers(self) -> Dict[str, ABCSeries]:
         for axis_name in self._AXIS_ORDERS:
             d.update(self._get_axis_resolvers(axis_name))
 
-        return {clean_column_name(k): v for k, v in d.items() if k is not int}
+        return {clean_column_name(k): v for k, v in d.items() if not isinstance(k, int)}
 
     def _get_cleaned_column_resolvers(self) -> Dict[str, ABCSeries]:
         """
@@ -476,7 +476,9 @@ def _get_cleaned_column_resolvers(self) -> Dict[str, ABCSeries]:
         if isinstance(self, ABCSeries):
             return {clean_column_name(self.name): self}
 
-        return {clean_column_name(k): v for k, v in self.items() if k is not int}
+        return {
+            clean_column_name(k): v for k, v in self.items() if not isinstance(k, int)
+        }
 
     @property
     def _info_axis(self):

pandas/tests/frame/test_query_eval.py

@@ -1076,6 +1076,7 @@ def df(self):
                 "that's": [9, 1, 8],
                 "☺": [8, 7, 6],
                 "foo#bar": [2, 4, 5],
+                1: [5, 7, 9],
             }
         )