fix(python,rust): Fix DataFrame.sum returning empty column names (#8283)

pola-rs · Apr 16, 2023 · abed1ee · abed1ee
1 parent 06289aa
commit abed1ee
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Showing 2 changed files with 9 additions and 1 deletion.
diff --git a/polars/polars-core/src/series/mod.rs b/polars/polars-core/src/series/mod.rs
@@ -544,7 +544,7 @@ impl Series {
         if self.is_empty()
             && (self.dtype().is_numeric() || matches!(self.dtype(), DataType::Boolean))
         {
-            return Series::new("", [0])
+            return Series::new(self.name(), [0])
                 .cast(self.dtype())
                 .unwrap()
                 .sum_as_series();

diff --git a/py-polars/tests/unit/test_df.py b/py-polars/tests/unit/test_df.py
@@ -3782,3 +3782,11 @@ def test_window_deadlock() -> None:
             pl.col("random").implode().over("names").alias("random/name"),
         ]
     )
+
+
+def test_sum_empty_column_names() -> None:
+    df = pl.DataFrame({"x": [], "y": []}, schema={"x": pl.Boolean, "y": pl.Boolean})
+    expected = pl.DataFrame(
+        {"x": [0], "y": [0]}, schema={"x": pl.UInt32, "y": pl.UInt32}
+    )
+    assert_frame_equal(df.sum(), expected)