Renames filenames according to the date they have been taken. A file will receive a name such as 2019-07-23_13-43-27_R0000666.jpg, where R0000666.jpg is the filename before renaming. Collisions are avoided, and files which already begin by "20" are not renamed.

rename_by_date.py

#!/usr/bin/python

import argparse
import os
import shutil
import subprocess

exifcmd = "/usr/local/bin/exiftool"

def main(args):
    for full_path in args.filenames:
        path, fn = os.path.split(full_path)
        if fn.startswith('20'):
            # We don't rename files that already begin with the year.
            print("Skipping %s" % full_path)
            continue
        process = subprocess.Popen([exifcmd, full_path], stdout=subprocess.PIPE)
        out, _ = process.communicate()
        exiflines = out.split('\n')
        for l in exiflines:
            if l.startswith("Create Date"):
                w = l.split()
                new_fn = w [-2] + "_" + w [-1] + "_" + fn
                new_fn = new_fn.replace(":", "-")
                new_fn = new_fn.replace(" ", "_")
                new_path = os.path.join(path, new_fn)
                # Checks that there is not a file already.
                while os.path.exists(new_path):
                    pieces = new_path.split(".")
                    pieces[-2] += '_b'
                    new_path = ".".join(pieces)
                shutil.move(full_path, new_path)
                print("%s --> %s" % (full_path, new_path))
                # Done for this file
                break

if __name__ == '__main__':
    parser = argparse.ArgumentParser()
    parser.add_argument('filenames', type=str, default=None,
                        nargs="*", help="Files to rename")
    args = parser.parse_args()
    main(args)