Fixed pandas-dev#38419 - BUG: set_index screws up the dtypes on empty DataFrames

Author: jordi-crespo

pandas/tests/frame/methods/test_set_index.py

@@ -53,12 +53,10 @@ def test_set_index_empty_dataframe(self):
             {"a": Series(dtype="datetime64[ns]"), "b": Series(dtype="int64"), "c": []}
         )
 
-        if df.empty:
-            df = DataFrame(columns=list(df.columns.values))
-
-        expected = df.set_index(["a", "b"])
-        assert (df.loc[:, ["a", "b"]].dtypes == expected.index.to_frame().dtypes).all()
-
+        expected = df.set_index(["a", "b"]).reset_index()
+        tm.assert_frame_equal(df.reset_index(drop = True),expected)
+        assert df.empty is True
+        
     def test_set_index_multiindexcolumns(self):
         columns = MultiIndex.from_tuples([("foo", 1), ("foo", 2), ("bar", 1)])
         df = DataFrame(np.random.randn(3, 3), columns=columns)