test: add test for describe method with mixed numeric and string columns

Author: kosiew

python/tests/test_dataframe.py

@@ -1870,6 +1870,20 @@ def test_describe(df):
     }
 
 
+def test_describe_mixed_numeric_string():
+    ctx = SessionContext()
+    batch = pa.RecordBatch.from_arrays(
+        [pa.array([1, 2, 3]), pa.array(["x", "y", "z"])],
+        names=["a", "b"],
+    )
+    df = ctx.from_arrow(batch)
+    result = df.describe().to_pydict()
+    assert result["a"][2] == 2.0
+    assert result["b"][2] in (None, "null")
+    assert result["b"][3] in (None, "null")
+    assert result["b"][6] in (None, "null")
+
+
 @pytest.mark.parametrize("path_to_str", [True, False])
 def test_write_csv(ctx, df, tmp_path, path_to_str):
     path = str(tmp_path) if path_to_str else tmp_path