done

lib/python3.11/site-packages/narwhals/_ibis/group_by.py

@@ -0,0 +1,32 @@
+from __future__ import annotations
+
+from typing import TYPE_CHECKING
+
+from narwhals._sql.group_by import SQLGroupBy
+
+if TYPE_CHECKING:
+    from collections.abc import Sequence
+
+    import ibis.expr.types as ir  # noqa: F401
+
+    from narwhals._ibis.dataframe import IbisLazyFrame
+    from narwhals._ibis.expr import IbisExpr
+
+
+class IbisGroupBy(SQLGroupBy["IbisLazyFrame", "IbisExpr", "ir.Value"]):
+    def __init__(
+        self,
+        df: IbisLazyFrame,
+        keys: Sequence[str] | Sequence[IbisExpr],
+        /,
+        *,
+        drop_null_keys: bool,
+    ) -> None:
+        frame, self._keys, self._output_key_names = self._parse_keys(df, keys=keys)
+        self._compliant_frame = frame.drop_nulls(self._keys) if drop_null_keys else frame
+
+    def agg(self, *exprs: IbisExpr) -> IbisLazyFrame:
+        native = self.compliant.native
+        return self.compliant._with_native(
+            native.group_by(self._keys).aggregate(*self._evaluate_exprs(exprs))
+        ).rename(dict(zip(self._keys, self._output_key_names)))