Support dataframe interchange protocol

packages/python/plotly/plotly/express/_core.py

@@ -7,6 +7,7 @@
 from _plotly_utils.basevalidators import ColorscaleValidator
 from plotly.colors import qualitative, sequential
 import math
+from packaging import version
 import pandas as pd
 import numpy as np
 
@@ -1307,7 +1308,15 @@ def build_dataframe(args, constructor):
     # Cast data_frame argument to DataFrame (it could be a numpy array, dict etc.)
     df_provided = args["data_frame"] is not None
     if df_provided and not isinstance(args["data_frame"], pd.DataFrame):
-        if hasattr(args["data_frame"], "to_pandas"):
+        if hasattr(args["data_frame"], "__dataframe__") and version.parse(
+            pd.__version__
+        ) >= version.parse("2.0.2"):
+            import pandas.api.interchange
+
+            df_not_pandas = args["data_frame"]
+            df_pandas = pandas.api.interchange.from_dataframe(df_not_pandas)
+            args["data_frame"] = df_pandas
+        elif hasattr(args["data_frame"], "to_pandas"):
             args["data_frame"] = args["data_frame"].to_pandas()
         else:
             args["data_frame"] = pd.DataFrame(args["data_frame"])

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

@@ -3,9 +3,22 @@
 import numpy as np
 import pandas as pd
 import pytest
+import unittest.mock as mock
 from plotly.express._core import build_dataframe
 from pandas.testing import assert_frame_equal
 
+# Fixtures
+# --------
+@pytest.fixture
+def add_interchange_module_for_old_pandas():
+    if not hasattr(pd.api, "interchange"):
+        pd.api.interchange = mock.MagicMock()
+        # to make the following import work: `import pandas.api.interchange`
+        with mock.patch.dict("sys.modules", {"pandas.api.interchange": pd.api.interchange}):
+            yield
+    else:
+        yield
+
 
 def test_numpy():
     fig = px.scatter(x=[1, 2, 3], y=[2, 3, 4], color=[1, 3, 9])
@@ -233,6 +246,24 @@ def test_build_df_with_index():
     assert_frame_equal(tips.reset_index()[out["data_frame"].columns], out["data_frame"])
 
 
+def test_build_df_using_interchange_protocol_mock(add_interchange_module_for_old_pandas):
+    class CustomDataFrame:
+        def __dataframe__(self):
+            pass
+
+    input_dataframe = CustomDataFrame()
+    args = dict(data_frame=input_dataframe, x="petal_width", y="sepal_length")
+
+    iris_pandas = px.data.iris()
+
+    with mock.patch("pandas.__version__", "2.0.2"):
+        with mock.patch(
+            "pandas.api.interchange.from_dataframe", return_value=iris_pandas
+        ) as mock_from_dataframe:
+            build_dataframe(args, go.Scatter)
+        mock_from_dataframe.assert_called_once_with(input_dataframe)
+
+
 def test_timezones():
     df = pd.DataFrame({"date": ["2015-04-04 19:31:30+1:00"], "value": [3]})
     df["date"] = pd.to_datetime(df["date"])