feat(python!): Default to raising on out-of-bounds indices in all get/gather operations

py-polars/polars/expr/array.py

@@ -441,7 +441,7 @@ def arg_max(self) -> Expr:
         """
         return wrap_expr(self._pyexpr.arr_arg_max())
 
-    def get(self, index: int | IntoExprColumn, *, null_on_oob: bool = True) -> Expr:
+    def get(self, index: int | IntoExprColumn, *, null_on_oob: bool = False) -> Expr:
         """
         Get the value by index in the sub-arrays.
 
@@ -503,7 +503,7 @@ def first(self) -> Expr:
         └───────────────┴───────┘
 
         """
-        return self.get(0)
+        return self.get(0, null_on_oob=True)
 
     def last(self) -> Expr:
         """
@@ -528,7 +528,7 @@ def last(self) -> Expr:
         └───────────────┴──────┘
 
         """
-        return self.get(-1)
+        return self.get(-1, null_on_oob=True)
 
     def join(self, separator: IntoExprColumn, *, ignore_nulls: bool = True) -> Expr:
         """

py-polars/polars/expr/list.py

@@ -505,7 +505,7 @@ def get(
         self,
         index: int | Expr | str,
         *,
-        null_on_oob: bool = True,
+        null_on_oob: bool = False,
     ) -> Expr:
         """
         Get the value by index in the sublists.
@@ -646,7 +646,7 @@ def first(self) -> Expr:
         │ [1, 2]    ┆ 1     │
         └───────────┴───────┘
         """
-        return self.get(0)
+        return self.get(0, null_on_oob=True)
 
     def last(self) -> Expr:
         """
@@ -667,7 +667,7 @@ def last(self) -> Expr:
         │ [1, 2]    ┆ 2    │
         └───────────┴──────┘
         """
-        return self.get(-1)
+        return self.get(-1, null_on_oob=True)
 
     def contains(
         self, item: float | str | bool | int | date | datetime | time | IntoExprColumn

py-polars/polars/series/array.py

@@ -338,7 +338,7 @@ def arg_max(self) -> Series:
 
         """
 
-    def get(self, index: int | IntoExprColumn, *, null_on_oob: bool = True) -> Series:
+    def get(self, index: int | IntoExprColumn, *, null_on_oob: bool = False) -> Series:
         """
         Get the value by index in the sub-arrays.
 

py-polars/polars/series/list.py

@@ -394,7 +394,7 @@ def get(
         self,
         index: int | Series | list[int],
         *,
-        null_on_oob: bool = True,
+        null_on_oob: bool = False,
     ) -> Series:
         """
         Get the value by index in the sublists.

py-polars/tests/unit/datatypes/test_list.py

@@ -792,9 +792,9 @@ def test_take_list_15719() -> None:
     )
     df = df.select(
         a_explode=pl.col("a").explode(),
-        a_get=pl.col("a").list.get(0),
+        a_get=pl.col("a").list.get(0, null_on_oob=True),
         b_explode=pl.col("b").explode(),
-        b_get=pl.col("b").list.get(0),
+        b_get=pl.col("b").list.get(0, null_on_oob=True),
     )
 
     expected_schema = pl.List(pl.Int64)

py-polars/tests/unit/operations/namespaces/list/test_list.py

@@ -878,8 +878,8 @@ def test_list_get_with_null() -> None:
     # 2. null element are not stored in `value` array.
     out = df.select(
         # For performance reasons, when-then-otherwise produces the list with layout-1.
-        layout1=pl.when(pl.col("b")).then([1, 2]).list.get(0),
-        layout2=pl.col("a").list.get(0),
+        layout1=pl.when(pl.col("b")).then([1, 2]).list.get(0, null_on_oob=False),
+        layout2=pl.col("a").list.get(0, null_on_oob=True),
     )
 
     expected = pl.DataFrame(