fix(pydeck): Support pandas 3.x compatibility without breaking pandas 2.x (#9988)

Replace module-based DataFrame detection with duck-typing to work with both pandas 2.x and 3.x module paths. Add defensive error handling in JSON serialization to prevent crashes from objects without __dict__. Includes additional tests for edge cases.

Fixes #9986

Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>

Author: chrisgervang

bindings/pydeck/pydeck/bindings/json_tools.py

@@ -72,7 +72,18 @@ def default_serialize(o, remap_function=lower_camel_case_keys):
     """Default method for rendering JSON from a dictionary"""
     if issubclass(type(o), PydeckType):
         return repr(o)
-    attrs = vars(o)
+
+    # Handle objects without __dict__ (e.g., pandas 3.x DataFrames if detection fails)
+    try:
+        attrs = vars(o)
+    except TypeError:
+        if hasattr(o, "to_dict") and callable(getattr(o, "to_dict", None)):
+            try:
+                return o.to_dict(orient="records")
+            except (TypeError, ValueError):
+                pass
+        return str(o)
+
     attrs = {k: v for k, v in attrs.items() if v is not None}
     for ignore_attr in IGNORE_KEYS:
         if ignore_attr in attrs:

bindings/pydeck/pydeck/data_utils/type_checking.py

@@ -6,7 +6,19 @@ def is_pandas_df(obj):
     bool
         Returns True if object is a Pandas DataFrame and False otherwise
     """
-    return obj.__class__.__module__ == "pandas.core.frame" and obj.to_records and obj.to_dict
+    # Use duck-typing approach that works with both pandas 2.x and 3.x
+    # Check for DataFrame-specific methods and the class name
+    try:
+        return (
+            obj.__class__.__name__ == "DataFrame"
+            and hasattr(obj, "to_records")
+            and hasattr(obj, "to_dict")
+            and hasattr(obj, "columns")
+            and callable(getattr(obj, "to_records", None))
+            and callable(getattr(obj, "to_dict", None))
+        )
+    except (AttributeError, TypeError):
+        return False
 
 
 def has_geo_interface(obj):

bindings/pydeck/tests/test_data_utils.py

@@ -49,6 +49,35 @@ def test_is_pandas_df():
     assert is_pandas_df(pd.DataFrame())
 
 
+def test_is_pandas_df_negative_cases():
+    """Test that is_pandas_df correctly rejects non-DataFrame objects"""
+    assert not is_pandas_df(None)
+    assert not is_pandas_df([1, 2, 3])
+    assert not is_pandas_df({"a": 1})
+    assert not is_pandas_df("string")
+    assert not is_pandas_df(42)
+
+    # Test object with some but not all DataFrame methods
+    class FakeDataFrame:
+        def to_records(self):
+            pass
+
+    assert not is_pandas_df(FakeDataFrame())
+
+
+def test_is_pandas_df_duck_typing():
+    """Test that is_pandas_df works with DataFrame duck-typing"""
+    df = pd.DataFrame({"a": [1, 2, 3]})
+    assert is_pandas_df(df)
+
+    # Verify the methods we rely on exist and are callable
+    assert hasattr(df, "to_records")
+    assert hasattr(df, "to_dict")
+    assert hasattr(df, "columns")
+    assert callable(df.to_records)
+    assert callable(df.to_dict)
+
+
 def test_compute_view():
     actual = compute_view(POINTS, 0.95, ViewState)
     actual_pandas = compute_view(pd.DataFrame(POINTS), 0.95, ViewState)