Add mypy optional error codes (#4054)

py-polars/polars/internals/functions.py

@@ -151,7 +151,7 @@ def concat(
 
 def _ensure_datetime(value: date | datetime) -> tuple[datetime, bool]:
     is_date_type = False
-    if isinstance(value, date) and not isinstance(value, datetime):
+    if not isinstance(value, datetime):
         value = datetime(value.year, value.month, value.day)
         is_date_type = True
     return value, is_date_type

py-polars/polars/internals/lazy_frame.py

@@ -1484,7 +1484,7 @@ def join(
     def with_columns(
         self: LDF,
         exprs: pli.Expr | pli.Series | Sequence[pli.Expr | pli.Series] | None = None,
-        **named_exprs: pli.Expr | pli.Series,
+        **named_exprs: pli.Expr | pli.Series | str,
     ) -> LDF:
         """
         Add or overwrite multiple columns in a DataFrame.
@@ -1534,21 +1534,22 @@ def with_columns(
         >>> ldf.with_columns(
         ...     d=pl.col("a") * pl.col("b"),
         ...     e=pl.col("c").is_not(),
+        ...     f="foo",
         ... ).collect()
-        shape: (4, 5)
-        ┌─────┬──────┬───────┬──────┬───────┐
-        │ a   ┆ b    ┆ c     ┆ d    ┆ e     │
-        │ --- ┆ ---  ┆ ---   ┆ ---  ┆ ---   │
-        │ i64 ┆ f64  ┆ bool  ┆ f64  ┆ bool  │
-        ╞═════╪══════╪═══════╪══════╪═══════╡
-        │ 1   ┆ 0.5  ┆ true  ┆ 0.5  ┆ false │
-        ├╌╌╌╌╌┼╌╌╌╌╌╌┼╌╌╌╌╌╌╌┼╌╌╌╌╌╌┼╌╌╌╌╌╌╌┤
-        │ 2   ┆ 4.0  ┆ true  ┆ 8.0  ┆ false │
-        ├╌╌╌╌╌┼╌╌╌╌╌╌┼╌╌╌╌╌╌╌┼╌╌╌╌╌╌┼╌╌╌╌╌╌╌┤
-        │ 3   ┆ 10.0 ┆ false ┆ 30.0 ┆ true  │
-        ├╌╌╌╌╌┼╌╌╌╌╌╌┼╌╌╌╌╌╌╌┼╌╌╌╌╌╌┼╌╌╌╌╌╌╌┤
-        │ 4   ┆ 13.0 ┆ true  ┆ 52.0 ┆ false │
-        └─────┴──────┴───────┴──────┴───────┘
+        shape: (4, 6)
+        ┌─────┬──────┬───────┬──────┬───────┬─────┐
+        │ a   ┆ b    ┆ c     ┆ d    ┆ e     ┆ f   │
+        │ --- ┆ ---  ┆ ---   ┆ ---  ┆ ---   ┆ --- │
+        │ i64 ┆ f64  ┆ bool  ┆ f64  ┆ bool  ┆ str │
+        ╞═════╪══════╪═══════╪══════╪═══════╪═════╡
+        │ 1   ┆ 0.5  ┆ true  ┆ 0.5  ┆ false ┆ foo │
+        ├╌╌╌╌╌┼╌╌╌╌╌╌┼╌╌╌╌╌╌╌┼╌╌╌╌╌╌┼╌╌╌╌╌╌╌┼╌╌╌╌╌┤
+        │ 2   ┆ 4.0  ┆ true  ┆ 8.0  ┆ false ┆ foo │
+        ├╌╌╌╌╌┼╌╌╌╌╌╌┼╌╌╌╌╌╌╌┼╌╌╌╌╌╌┼╌╌╌╌╌╌╌┼╌╌╌╌╌┤
+        │ 3   ┆ 10.0 ┆ false ┆ 30.0 ┆ true  ┆ foo │
+        ├╌╌╌╌╌┼╌╌╌╌╌╌┼╌╌╌╌╌╌╌┼╌╌╌╌╌╌┼╌╌╌╌╌╌╌┼╌╌╌╌╌┤
+        │ 4   ┆ 13.0 ┆ true  ┆ 52.0 ┆ false ┆ foo │
+        └─────┴──────┴───────┴──────┴───────┴─────┘
         """
         if named_exprs and not Config.with_columns_kwargs:
             raise RuntimeError(

py-polars/polars/io.py

@@ -209,7 +209,7 @@ def read_csv(
 
     if columns and not has_header:
         for column in columns:
-            if isinstance(column, str) and not column.startswith("column_"):
+            if not column.startswith("column_"):
                 raise ValueError(
                     'Specified column names do not start with "column_", '
                     "but autogenerated header names were requested."

py-polars/polars/testing.py

@@ -188,7 +188,10 @@ def assert_series_equal(
     """
     obj = "Series"
 
-    if not (isinstance(left, Series) and isinstance(right, Series)):
+    if not (
+        isinstance(left, Series)  # type: ignore[redundant-expr]
+        and isinstance(right, Series)
+    ):
         raise_assert_detail(obj, "Type mismatch", type(left), type(right))
 
     if left.shape != right.shape:

py-polars/pyproject.toml

@@ -41,6 +41,12 @@ warn_redundant_casts = true
 # no_implicit_reexport = true
 # strict_equality = true
 # TODO: When all flags are enabled, replace by strict = true
+enable_error_code = [
+  "redundant-expr",
+  "truthy-bool",
+  # TODO: Uncomment error below and fix mypy errors
+  # "ignore-without-code",
+]
 
 [[tool.mypy.overrides]]
 module = ["pyarrow.*", "polars.polars", "matplotlib.*", "fsspec.*", "connectorx", "IPython.*"]