code: def really_bad_du(path):
      "Don't actually use this, it's just an example."
      return sum([os.path.getsize(fp) for fp in list_files(path)]f really_bad_du(path):
      "Don't actually use this, it's just an example."
      return sum([os.path.getsize(fp) for fp in list_files(path)])
docs: Don't actually use this, it's just an example.