additional tests for adding empty dataframes of different dtypes

Author: rekcahpassyla

pandas/tests/test_frame.py

@@ -5129,10 +5129,16 @@ def test_operators(self):
         df = DataFrame({'a': ['a', None, 'b']})
         assert_frame_equal(df + df, DataFrame({'a': ['aa', np.nan, 'bb']}))
 
-        df = DataFrame()
-        self.assertTrue((df + df).equals(DataFrame()))
-        assert_frame_equal(df + df, DataFrame())
+        # Test for issue #10181
+        for dtype in ('float', 'int64'):
+            df = DataFrame(dtype=dtype)
+            self.assertTrue((df + df).equals(DataFrame(dtype=dtype)))
+            assert_frame_equal(df + df, DataFrame(dtype=dtype))
+
+            df = DataFrame(columns=['A'], dtype=dtype)
+            self.assertTrue((df + df).equals(df))
 
+        
 
     def test_ops_np_scalar(self):
         vals, xs = np.random.rand(5, 3), [nan, 7, -23, 2.718, -3.14, np.inf]