MP4 to MP3 file stitcher

stitcher.py

import os
import re
import subprocess

DIRECTORY = "/Users/aparagas/Downloads/td_friends"

os.chdir(DIRECTORY)

# Ensure all MP3 files are deleted
for file in os.listdir(os.getcwd()):
  if ".mp3" in file:
    os.remove(file)

# Ensure MP4 files formatted nicely, convert to MP3 files
for file in os.listdir(os.getcwd()):
  if not os.path.isfile(file):
    continue
  if ".mp4" not in file:
    continue
  file_name_simple = re.search(r'\d+', file)
  if file_name_simple is None:
    continue
    
  file_name_simple = file_name_simple.group()
  os.rename(
    file, 
    "{name}.mp4".format(name=file_name_simple)
  )
  subprocess.call("ffmpeg -i {name}.mp4 {name}.mp3".format(
    name=file_name_simple
  ), shell=True)

# Stitch MP3 files together to 1 MP3 file
subprocess.call(
  "ffmpeg -i \"concat:{files}\" output.mp3".format(
    files="|".join(
      sorted([
        file
        for file in os.listdir(os.getcwd())
        if os.path.isfile(file)
        if ".mp3" in file
      ], key=lambda x: int(x.split(".mp3", 1)[0]))
    )
  ),
  shell=True
)