Update flake8 settings (#4038)

py-polars/.flake8

@@ -1,7 +1,12 @@
 [flake8]
-# just stop shouting as black decides line lengths.
-max-line-length = 180
-# E203, W503: due to black fmt
-ignore = E203,W503
-exclude = docs, venv, target
-
+# Satisfy black: https://black.readthedocs.io/en/stable/guides/using_black_with_other_tools.html#flake8
+# TODO: Handle long lines adequately
+max-line-length = 160
+extend-ignore = E203
+per-file-ignores =
+    __init__.py:F401
+    tests/*.py: E101, W191
+extend-exclude =
+    # Automatically generated test artifacts
+    venv/,
+    target/,

py-polars/polars/__init__.py

@@ -1,9 +1,8 @@
-# flake8: noqa
 import warnings
 
 try:
     from polars.polars import version
-except ImportError as e:  # pragma: no cover
+except ImportError:  # pragma: no cover
 
     def version() -> str:
         return ""
@@ -12,10 +11,7 @@ def version() -> str:
     warnings.warn("polars binary missing!")
 
 import polars.testing as testing
-from polars.cfg import (  # flake8: noqa. We do not export in __all__
-    Config,
-    toggle_string_cache,
-)
+from polars.cfg import Config, toggle_string_cache  # We do not export in __all__
 from polars.convert import (
     from_arrow,
     from_dict,
@@ -61,10 +57,7 @@ def version() -> str:
     ShapeError,
 )
 from polars.internals.expr import Expr
-from polars.internals.frame import (  # flake8: noqa # TODO: remove need for wrap_df
-    DataFrame,
-    wrap_df,
-)
+from polars.internals.frame import DataFrame, wrap_df  # TODO: remove need for wrap_df
 from polars.internals.functions import concat, date_range, get_dummies
 from polars.internals.io import read_ipc_schema, read_parquet_schema
 from polars.internals.lazy_frame import LazyFrame
@@ -113,10 +106,7 @@ def version() -> str:
 )
 from polars.internals.lazy_functions import to_list as list
 from polars.internals.lazy_functions import var
-from polars.internals.series import (  # flake8: noqa # TODO: remove need for wrap_s
-    Series,
-    wrap_s,
-)
+from polars.internals.series import Series, wrap_s  # TODO: remove need for wrap_s
 from polars.internals.whenthen import when
 from polars.io import (
     read_avro,

py-polars/polars/_html.py

@@ -42,7 +42,12 @@ def __exit__(
 
 
 class HTMLFormatter:
-    def __init__(self, df: DataFrame, max_cols: int = 75, max_rows: int = 40):  # type: ignore  # noqa
+    def __init__(
+        self,
+        df: DataFrame,  # type: ignore[name-defined] # noqa: F821
+        max_cols: int = 75,
+        max_rows: int = 40,
+    ):
         self.df = df
         self.elements: list[str] = []
         self.max_cols = max_cols

py-polars/polars/internals/__init__.py

@@ -1,4 +1,3 @@
-# flake8: noqa
 """
 The modules within `polars.internals` are interdependent. To prevent cyclical imports, they all import from each other
 via this __init__ file using `import polars.internals as pli`. The imports below are being shared across this module.

py-polars/polars/internals/frame.py

@@ -1071,7 +1071,7 @@ def write_json(
 
     def to_pandas(
         self, *args: Any, date_as_object: bool = False, **kwargs: Any
-    ) -> pd.DataFrame:  # noqa: F821
+    ) -> pd.DataFrame:
         """
         Cast to a pandas DataFrame.
         This requires that pandas and pyarrow are installed.

py-polars/tests/io/test_avro.py

@@ -1,8 +1,6 @@
-# flake8: noqa: W191,E101
 from __future__ import annotations
 
 import os
-from typing import List
 
 import pytest
 

py-polars/tests/io/test_csv.py

@@ -1,4 +1,3 @@
-# flake8: noqa: W191,E101
 from __future__ import annotations
 
 import gzip

py-polars/tests/io/test_ipc.py

@@ -1,10 +1,8 @@
-# flake8: noqa: W191,E101
 from __future__ import annotations
 
 import io
 import os
 from pathlib import Path
-from typing import List
 
 import pandas as pd
 import pytest

py-polars/tests/io/test_json.py

@@ -1,11 +1,8 @@
-# flake8: noqa: W191,E101
 from __future__ import annotations
 
 import io
 import os
 
-import pytest
-
 import polars as pl
 
 

py-polars/tests/io/test_lazy_csv.py

@@ -1,7 +1,5 @@
-# flake8: noqa: W191,E101
 from __future__ import annotations
 
-import io
 from os import path
 from pathlib import Path
 

py-polars/tests/io/test_lazy_ipc.py

@@ -1,4 +1,3 @@
-# flake8: noqa: W191,E101
 from __future__ import annotations
 
 import polars as pl

py-polars/tests/io/test_lazy_parquet.py

@@ -1,4 +1,3 @@
-# flake8: noqa: W191,E101
 from __future__ import annotations
 
 from os import path

py-polars/tests/io/test_other.py

@@ -1,4 +1,3 @@
-# flake8: noqa: W191,E101
 from __future__ import annotations
 
 import copy

py-polars/tests/io/test_parquet.py

@@ -1,9 +1,7 @@
-# flake8: noqa: W191,E101
 from __future__ import annotations
 
 import io
 import os
-from typing import List
 
 import numpy as np
 import pandas as pd

py-polars/tests/io/test_sql.py

@@ -11,7 +11,7 @@ def test_read_sql() -> None:
     import tempfile
 
     try:
-        import connectorx  # noqa
+        import connectorx  # noqa: F401
 
         with tempfile.TemporaryDirectory() as tmpdir_name:
             test_db = os.path.join(tmpdir_name, "test.db")

py-polars/tests/test_df.py

@@ -1,12 +1,11 @@
-# flake8: noqa: W191,E101
 from __future__ import annotations
 
 import sys
 import typing
 from builtins import range
 from datetime import date, datetime, timedelta
 from io import BytesIO
-from typing import Any, Iterator, Type
+from typing import Any, Iterator
 from unittest.mock import patch
 
 import numpy as np
@@ -24,7 +23,7 @@
 
 
 def test_version() -> None:
-    _version = pl.__version__
+    pl.__version__
 
 
 def test_null_count() -> None:
@@ -1622,7 +1621,7 @@ def test_apply_dataframe_return() -> None:
     assert out.frame_equal(expected, null_equal=True)
 
 
-def test_groupby_cat_list() -> None:  # noqa: W191,E101
+def test_groupby_cat_list() -> None:
     grouped = (
         pl.DataFrame(
             [
@@ -2152,9 +2151,9 @@ def test_join_suffixes() -> None:
 
     for how in ["left", "inner", "outer", "cross"]:
         # no need for an assert, we error if wrong
-        _df = df_a.join(df_b, on="A", suffix="_y", how=how)["B_y"]
+        df_a.join(df_b, on="A", suffix="_y", how=how)["B_y"]
 
-    _df = df_a.join_asof(df_b, on="A", suffix="_y")["B_y"]
+    df_a.join_asof(df_b, on="A", suffix="_y")["B_y"]
 
 
 def test_preservation_of_subclasses() -> None: