Fixed code breakage for tuples for axis = 0

PEP error fixed

Modified previous commit

Author: rajat315315

pandas/core/apply.py

@@ -482,7 +482,7 @@ def wrap_results_for_axis(
             return res
 
         elif self.result_type is None and all(
-            isinstance(x, dict) for x in results.values()
+            isinstance(x, (dict, tuple)) for x in results.values()
         ):
             # Our operation was a to_dict op e.g.
             #  test_apply_dict GH#8735, test_apply_reduce_to_dict GH#25196 #37544

pandas/tests/apply/test_frame_apply.py

@@ -131,6 +131,14 @@ def test_apply_funcs_over_empty(self, func):
         expected = getattr(df, func)()
         tm.assert_series_equal(result, expected)
 
+    def test_apply_return_type_none(self):
+        # GH 35518
+        df = DataFrame([["orig1", "orig2"], ["orig3", "orig4"]])
+        result = df.apply(func=lambda col: ("new1", "new2"))
+
+        expected = Series(data=[("new1", "new2"), ("new1", "new2")])
+        tm.assert_series_equal(result, expected)
+
     def test_nunique_empty(self):
         # GH 28213
         df = DataFrame(columns=["a", "b", "c"])