TST: add test for df construction from dict with tuples (pandas-dev#2…

…9497)

* add test for frame construction from dict with tuples

* parametrize full data_dict

* refactor parametrize

pandas/tests/frame/test_constructors.py

@@ -1424,6 +1424,23 @@ def test_from_dict_columns_parameter(self):
                 dict([("A", [1, 2]), ("B", [4, 5])]), columns=["one", "two"]
             )
 
+    @pytest.mark.parametrize(
+        "data_dict, keys",
+        [
+            ([{("a",): 1}, {("a",): 2}], [("a",)]),
+            ([OrderedDict([(("a",), 1), (("b",), 2)])], [("a",), ("b",)]),
+            ([{("a", "b"): 1}], [("a", "b")]),
+        ],
+    )
+    def test_constructor_from_dict_tuples(self, data_dict, keys):
+        # GH 16769
+        df = DataFrame.from_dict(data_dict)
+
+        result = df.columns
+        expected = Index(keys, dtype="object", tupleize_cols=False)
+
+        tm.assert_index_equal(result, expected)
+
     def test_constructor_Series_named(self):
         a = Series([1, 2, 3], index=["a", "b", "c"], name="x")
         df = DataFrame(a)