Set the correct line ending, either CRLF or LF, for a directory tree

reset_line_ending.py

#!/usr/bin/env python3
#
# Sample Usage:
#   <command> '.*\.html'

import logging
import os
import re
from argparse import ArgumentParser

logging.basicConfig(format='%(asctime)-15s %(message)s', level=logging.DEBUG)
logger = logging.getLogger(__file__)


def discover_and_process(pattern: str):
    for current_dir, dirs, files in os.walk('.'):
        for name in files:
            if re.match(pattern, name):
                path = os.path.join(current_dir, name)
                process_file(path)
    logger.info("finished")


def process_file(path: str):
    with open(path, 'r') as f:
        text = f.read()
    # Python `open` will set the end-of-line characters correctly
    with open(path, 'w') as f:
        f.write(text)
    logger.info('Changed %s', path)


def main():
    parser = ArgumentParser()
    parser.add_argument('pattern', type=str, help='Regex pattern for file names')
    args = parser.parse_args()
    logger.info('Arguments = %s', args)

    pattern = args.pattern
    discover_and_process(pattern)


if __name__ == '__main__':
    main()