Add numerical ids to filename of every file in directory by renaming. Useful for zettelkasten.

add_ids_in_filenames.py

import os
import sys
import re
from pathlib import Path

# Run: python3 add_ids_in_filenames.py path_to_your_folder
# Behavior: Scans the folder, takes all files without an ID at the beginning
# consisting of 10 digits, and renames them all to add such an id to them.
# Ids are genrerated serially.
# Before renaming, checks for exact name collision not to overwrite something.
# Ignores already tagged files.
# Does not check for ID-collisions in already existing files.

# Useful for e.g. establishing a zettelkasten note system.

START_ID = 1
ID_LEN = 10

curr_id = START_ID

def pad(num):
    s = str(num)
    assert len(s) <= ID_LEN
    zeros = "0"*(ID_LEN - len(s))
    return zeros + s

def next_id():
    global curr_id
    ans = pad(curr_id)
    curr_id += 1
    return ans

def main():
    if(len(sys.argv) != 2):
        print("Need 2 args")
        return

    folder = sys.argv[1]
    print("Gonna operate on folder: " + folder)

    top, dirs, files = next(os.walk(folder))
    print(files)
    to_process = []
    pat = re.compile("^\d{%d}" % ID_LEN)
    for filename in files:
        if pat.match(filename):
            print(filename)
        else:
            to_process.append(filename)

    for fn in to_process:
        id = next_id()
        new_name = id + " " + fn
        old_path = Path(top, fn)
        new_path = Path(top, new_name)
        if new_path.exists():
            print("Skipping " + fn + " because of collision.")
            continue
        print("Want to rename " + str(old_path) + " to " + str(new_path))
        os.rename(old_path, new_path)


main()