Unit test that checks for PEP8 faults in a Django project using pytest

test_pep8.py

import os
import sys

import pycodestyle

from django.conf import settings


class PEP8Error(BaseException):
    pass


def error_print(*args, **kwargs):
    print(*args, file=sys.stderr, **kwargs)


def test_pep8():
    style = pycodestyle.StyleGuide(config_file=os.path.join(settings.BASE_DIR, 'tox.ini'))
    py_files = []

    for root, dirs, files in os.walk(settings.BASE_DIR):
        for file in files:
            if file.endswith(".py"):
                py_files.append(os.path.join(root, file))

    pep8_check = style.check_files(py_files)
    if pep8_check.total_errors > 0:
        for err in pep8_check.messages:
            error_print(err)
        raise PEP8Error('PEP8 misconducts have been found; check stderr.')