Added test for ensuring empty df has an empty index.

Author: Sumanau Sareen

pandas/core/frame.py

@@ -3402,7 +3402,7 @@ def _ensure_valid_index(self, value):
         passed value.
         """
         # GH5632, make sure that we are a Series convertible
-        if not len(self.index) and len(value) and is_list_like(value):
+        if not len(self.index) and is_list_like(value) and len(value):
             try:
                 value = Series(value)
             except (ValueError, NotImplementedError, TypeError):

pandas/tests/indexing/test_indexing.py

@@ -717,6 +717,11 @@ def test_index_type_coercion(self):
                     idxr(s2)['0'] = 0
                     assert s2.index.is_object()
 
+    def test_empty_index_for_empty_dataframe(self):
+        empty_df = pd.DataFrame(columns=['A'])
+        df_with_empty_value = pd.DataFrame(columns=['A'], data=[])
+        assert df_with_empty_value.index.dtype == empty_df.index.dtype
+
 
 class TestMisc(Base):