pre_commit_hooks/tests_should_end_in_test.py

import sys


def validate_files(argv):
    retcode = 0
    for filename in argv:
        if (
            not filename.endswith('_test.py') and
            not filename.endswith('__init__.py') and
            not filename.endswith('/conftest.py')
        ):
            retcode = 1
            print '{0} does not end in _test.py'.format(filename)

    return retcode


def entry():
    validate_files(sys.argv[1:])


if __name__ == '__main__':
    sys.exit(entry())