Merge pull request #77 from raisadz/feat/explode

feat: add `explode` and `sink_parquet`

Author: MarcoGorelli

narwhals

@@ -28,6 +28,8 @@
 
 if TYPE_CHECKING:
     from collections.abc import Iterable, Iterator, Mapping, Sequence
+    from io import BytesIO
+    from pathlib import Path
     from types import ModuleType
 
     from narwhals._compliant.typing import CompliantDataFrameAny
@@ -377,12 +379,16 @@ def group_by(
     ) -> DaftLazyGroupBy:
         return DaftLazyGroupBy(self, keys, drop_null_keys=drop_null_keys)
 
+    def explode(self, columns: Sequence[str]) -> DaftLazyFrame:
+        return self._with_native(self.native.explode(*columns))
+
+    def sink_parquet(self, file: str | Path | BytesIO) -> None:
+        self.native.write_parquet(str(file))
+
     gather_every = not_implemented.deprecated(
         "`LazyFrame.gather_every` is deprecated and will be removed in a future version."
     )
     join_asof = not_implemented()
     tail = not_implemented.deprecated(
         "`LazyFrame.tail` is deprecated and will be removed in a future version."
     )
-    explode = not_implemented()
-    sink_parquet = not_implemented()

narwhals_daft/dataframe.py

@@ -30,9 +30,7 @@
     "test_dt_to_string_iso_local_datetime_expr",
     "test_empty_scalar_reduction_with_columns",
     "test_explode_invalid_operation_error",
-    "test_explode_multiple_cols",
     "test_explode_shape_error",
-    "test_explode_single_col",
     "test_expr_binary",
     "test_expr_floordiv_by_zero",
     "test_expr_rfloordiv_by_zero",