BLD: Run flake8 check on Cython files in pre-commit (#30847)

Author: xhochy

.pre-commit-config.yaml

@@ -10,6 +10,20 @@ repos:
     -   id: flake8
         language: python_venv
         additional_dependencies: [flake8-comprehensions>=3.1.0]
+    -   id: flake8
+        name: flake8-pyx
+        language: python_venv
+        files: \.(pyx|pxd)$
+        types:
+          - file
+        args: [--append-config=flake8/cython.cfg]
+    -   id: flake8
+        name: flake8-pxd
+        language: python_venv
+        files: \.pxi\.in$
+        types:
+          - file
+        args: [--append-config=flake8/cython-template.cfg]
 -   repo: https://github.com/pre-commit/mirrors-isort
     rev: v4.3.21
     hooks:

ci/code_checks.sh

@@ -65,12 +65,12 @@ if [[ -z "$CHECK" || "$CHECK" == "lint" ]]; then
     flake8 --format="$FLAKE8_FORMAT" .
     RET=$(($RET + $?)) ; echo $MSG "DONE"
 
-    MSG='Linting .pyx code' ; echo $MSG
-    flake8 --format="$FLAKE8_FORMAT" pandas --filename=*.pyx --select=E501,E302,E203,E111,E114,E221,E303,E128,E231,E126,E265,E305,E301,E127,E261,E271,E129,W291,E222,E241,E123,F403,C400,C401,C402,C403,C404,C405,C406,C407,C408,C409,C410,C411
+    MSG='Linting .pyx and .pxd code' ; echo $MSG
+    flake8 --format="$FLAKE8_FORMAT" pandas --append-config=flake8/cython.cfg
     RET=$(($RET + $?)) ; echo $MSG "DONE"
 
-    MSG='Linting .pxd and .pxi.in' ; echo $MSG
-    flake8 --format="$FLAKE8_FORMAT" pandas/_libs --filename=*.pxi.in,*.pxd --select=E501,E302,E203,E111,E114,E221,E303,E231,E126,F403
+    MSG='Linting .pxi.in' ; echo $MSG
+    flake8 --format="$FLAKE8_FORMAT" pandas/_libs --append-config=flake8/cython-template.cfg
     RET=$(($RET + $?)) ; echo $MSG "DONE"
 
     echo "flake8-rst --version"

flake8/cython-template.cfg

@@ -0,0 +1,4 @@
+[flake8]
+filename = *.pxi.in
+select = E501,E302,E203,E111,E114,E221,E303,E231,E126,F403
+

flake8/cython.cfg

@@ -0,0 +1,3 @@
+[flake8]
+filename = *.pyx,*.pxd
+select=E501,E302,E203,E111,E114,E221,E303,E128,E231,E126,E265,E305,E301,E127,E261,E271,E129,W291,E222,E241,E123,F403,C400,C401,C402,C403,C404,C405,C406,C407,C408,C409,C410,C411

pandas/_libs/sparse_op_helper.pxi.in

@@ -235,7 +235,7 @@ cdef inline tuple int_op_{{opname}}_{{dtype}}({{dtype}}_t[:] x_,
                                               {{dtype}}_t yfill):
     cdef:
         IntIndex out_index
-        Py_ssize_t xi = 0, yi = 0, out_i = 0 # fp buf indices
+        Py_ssize_t xi = 0, yi = 0, out_i = 0  # fp buf indices
         int32_t xloc, yloc
         int32_t[:] xindices, yindices, out_indices
         {{dtype}}_t[:] x, y

pandas/_libs/tslibs/util.pxd

@@ -42,7 +42,7 @@ cdef extern from "numpy/ndarrayobject.h":
     bint PyArray_IsIntegerScalar(obj) nogil
     bint PyArray_Check(obj) nogil
 
-cdef extern from  "numpy/npy_common.h":
+cdef extern from "numpy/npy_common.h":
     int64_t NPY_MIN_INT64
 
 

web/pandas_web.py

@@ -34,12 +34,13 @@
 import time
 import typing
 
-import feedparser
 import jinja2
-import markdown
 import requests
 import yaml
 
+import feedparser
+import markdown
+
 
 class Preprocessors:
     """