docs: implement ruff recommendation

Author: kosiew

python/datafusion/expr.py

@@ -384,8 +384,11 @@ def literal(value: Any) -> Expr:
     def utf8_literal(value: str) -> Expr:
         """Creates a new expression representing a UTF8 literal value.
 
-        It is different from `literal` because it is pa.string() instead of pa.string_view()
-        This is needed for cases where datafusion is expecting a utf8 instead of utf8view literal like in
+        It is different from `literal` because it is pa.string() instead of
+        pa.string_view()
+
+        This is needed for cases where DataFusion is expecting a UTF8 instead of
+        UTF8View literal, like in:
         https://github.com/apache/datafusion/blob/86740bfd3d9831d6b7c1d0e1bf4a21d91598a0ac/datafusion/functions/src/core/arrow_cast.rs#L179
         """
         if isinstance(value, str):

python/tests/test_functions.py

@@ -911,8 +911,8 @@ def test_temporal_functions(df):
 
 def test_arrow_cast(df):
     df = df.select(
-        # we use `utf8_literal` to returns utf8 instead of `literal` which returns utf8view
-        # because datafusion.arrow_cast # expects a utf8 instead of utf8view
+        # we use `utf8_literal` to returns utf8 instead of `literal` which returns
+        # utf8view # because datafusion.arrow_cast expects a utf8 instead of utf8view
         # https://github.com/apache/datafusion/blob/86740bfd3d9831d6b7c1d0e1bf4a21d91598a0ac/datafusion/functions/src/core/arrow_cast.rs#L179
         f.arrow_cast(column("b"), utf8_literal("Float64")).alias("b_as_float"),
         f.arrow_cast(column("b"), utf8_literal("Int32")).alias("b_as_int"),