pyrename

#!/usr/bin/env python3
# Author: github.com/danielhoherd
# License: MIT
"""Regular expression renaming of files.

This was inspired Robin Barker's prename tool. It does not handle
emoji's, so a modern implementation was needed.
"""

import argparse
import re
from pathlib import Path
from sys import exit, stderr


def main():
    parser = argparse.ArgumentParser(description=__doc__, formatter_class=argparse.RawDescriptionHelpFormatter)
    parser.add_argument("--ignore-case", "-i", action="store_true", help="Ignore case in regex match")
    parser.add_argument("--dry-run", "-n", action="store_true", help="Dry run (do not actually rename)")
    parser.add_argument("--verbose", "-v", action="store_true", help="Be verbose", default=False)
    parser.add_argument("match", help="Regex to match", type=str)
    parser.add_argument("sub", help="Regex substitution", type=str)
    parser.add_argument("filenames", nargs="*", help="Files to rename")
    args = parser.parse_args()

    def eprint(thing):
        print(thing, file=stderr)

    if len(args.filenames) == 0:
        eprint("Error: no files given")
        exit(1)

    for filename in args.filenames:
        try:
            old_name = Path(filename)
            if not old_name.exists():
                eprint(f"Error: {old_name} does not exists")
                continue

            re_flags = re.IGNORECASE if args.ignore_case else 0

            new_name = Path(re.sub(args.match, args.sub, filename, flags=re_flags))

            if old_name == new_name:
                print(f"No changes needed: {new_name}")
                continue

            if new_name.exists():
                eprint(f"Error: {new_name} exists already")
                continue

            if args.dry_run:
                eprint(f"Would rename: {filename} -> {new_name}")
                continue

            if args.verbose:
                print(f"Renamed: {filename} -> {new_name}")

            old_name.rename(new_name)

        except (re.error, UnicodeEncodeError, OverflowError) as e:
            eprint(e)
            exit(1)


if __name__ == "__main__":
    try:
        exit(main())
    except KeyboardInterrupt:
        exit(1)