fix[rust]: fix Series::full_null for list dtype (#4407)

pola-rs · Aug 14, 2022 · d1dc004 · d1dc004
1 parent 0d503d9
commit d1dc004
Show file tree

Hide file tree

Showing 3 changed files with 14 additions and 6 deletions.
diff --git a/polars/polars-core/src/frame/mod.rs b/polars/polars-core/src/frame/mod.rs
@@ -470,7 +470,6 @@ impl DataFrame {
     /// Ensure all the chunks in the DataFrame are aligned.
     pub fn rechunk(&mut self) -> &mut Self {
         if self.should_rechunk() {
-            debug_assert!(!self.columns.iter().map(|s| s.n_chunks()).all_equal());
             self.as_single_chunk_par()
         } else {
             self

diff --git a/polars/polars-core/src/series/ops/null.rs b/polars/polars-core/src/series/ops/null.rs
@@ -2,13 +2,11 @@ use crate::prelude::*;
 
 impl Series {
     pub fn full_null(name: &str, size: usize, dtype: &DataType) -> Self {
-        if let DataType::List(dtype) = dtype {
-            let val = Series::full_null("", 0, dtype);
-            let avs = [AnyValue::List(val)];
-            return Series::new(name, avs.as_ref());
-        }
         // match the logical types and create them
         match dtype {
+            DataType::List(inner_dtype) => {
+                ListChunked::full_null_with_dtype(name, size, inner_dtype).into_series()
+            }
             #[cfg(feature = "dtype-categorical")]
             DataType::Categorical(_) => CategoricalChunked::full_null(name, size).into_series(),
             #[cfg(feature = "dtype-date")]

diff --git a/py-polars/tests/test_lists.py b/py-polars/tests/test_lists.py
@@ -402,3 +402,14 @@ def test_arr_contains_categorical() -> None:
     assert df_groups.filter(pl.col("str_list").arr.contains("C")).collect().to_dict(
         False
     ) == {"group": [2], "str_list": [["A", "C"]]}
+
+
+def test_list_diagonal_concat() -> None:
+    df1 = pl.DataFrame({"a": [1, 2]})
+
+    df2 = pl.DataFrame({"b": [[1]]})
+
+    assert pl.concat([df1, df2], how="diagonal").to_dict(False) == {
+        "a": [1, 2, None],
+        "b": [None, None, [1]],
+    }