convert between pickcle2 and pickcle3

pickle_convert.py

import pickle
import argparse
from os import listdir
from os.path import isfile, join
import sys
def convert(input_file_with_path, output_file_with_path):
  with open(input_file_with_path, 'rb') as f_in:
    data = pickle.load(f_in)
    with open(output_file_with_path, 'wb') as f_out:
        pickle.dump(data, f_out, protocol=2)
  print("converted {}".format(output_file_with_path))
if __name__ == "__main__":
  # FixMe
  parser = argparse.ArgumentParser()
  parser.add_argument("--input_dir", type=str, required=True, help="input dir")
  parser.add_argument("--output_dir", type=str, default=None, help="output dir")
  args, unknown = parser.parse_known_args(sys.argv)
  all_files = [f for f in listdir(args.input_dir) if isfile(join(args.input_dir, f))]
  for file in all_files:
    input_file_with_path = "{}/{}".format(args.input_dir, file)
    output_file_with_path = "{}/{}".format(args.output_dir, file)
    convert(input_file_with_path, output_file_with_path)