Test renaming of _groupby_function wrapper function

Author: Matt Hagy

pandas/tests/groupby/test_groupby.py

@@ -5320,6 +5320,12 @@ def test_tab_completion(self):
              'ffill', 'bfill', 'pad', 'backfill', 'rolling', 'expanding'])
         self.assertEqual(results, expected)
 
+    def test_groupby_function_rename(self):
+        grp = self.mframe.groupby(level='second')
+        for name in ['sum', 'prod', 'min', 'max', 'first', 'last']:
+            f = getattr(grp, name)
+            self.assertEqual(f.__name__, name)
+
     def test_lexsort_indexer(self):
         keys = [[nan] * 5 + list(range(100)) + [nan] * 5]
         # orders=True, na_position='last'