add changelog entry and test case

Signed-off-by: Anatoly Myachev <[email protected]>

Author: anmyachev

CHANGELOG.md

@@ -9,6 +9,7 @@ This project adheres to [Semantic Versioning](http://semver.org/).
 - Fix issue with creating dendrogram in subplots [[#4411](https://github.com/plotly/plotly.py/pull/4411)],
 - Fix issue with px.line not accepting "spline" line shape [[#2812](https://github.com/plotly/plotly.py/issues/2812)]
 - Fix KeyError when using column of `pd.Categorical` dtype with unobserved categories [[#4437](https://github.com/plotly/plotly.py/pull/4437)]
+- Fix dataframe interchange in case `column_names` returns an unmaterialized object: generator, iterator, etc. [[#4442]](https://github.com/plotly/plotly.py/pull/4442)
 
 ## [5.18.0] - 2023-10-25
 

packages/python/plotly/plotly/tests/test_optional/test_px/test_px_input.py

@@ -250,15 +250,21 @@ def test_build_df_with_index():
     assert_frame_equal(tips.reset_index()[out["data_frame"].columns], out["data_frame"])
 
 
+@pytest.mark.parametrize("column_names_as_generator", [False, True])
 def test_build_df_using_interchange_protocol_mock(
-    add_interchange_module_for_old_pandas,
+    add_interchange_module_for_old_pandas, column_names_as_generator
 ):
     class InterchangeDataFrame:
         def __init__(self, columns):
             self._columns = columns
 
-        def column_names(self):
-            return self._columns
+        if column_names_as_generator:
+            def column_names(self):
+                for col in self._columns:
+                    yield col
+        else:
+            def column_names(self):
+                return self._columns
 
     interchange_dataframe = InterchangeDataFrame(
         ["petal_width", "sepal_length", "sepal_width"]