import pickle

custom_dict = {'key': 'value'}

def save_file(data, file_name):
  with open(file_name + '.pickle', 'wb') as handle:
    pickle.dump(data, handle, protocol=pickle.HIGHEST_PROTOCOL)

def read_file(file_name):
  with open(file_name + '.pickle', 'rb') as handle:
    return pickle.load(handle)

save_file(custom_dict, 'custom_dict')

new_custom_dict = read_file('custom_dict')

print(new_custom_dict == custom_dict)