if os.path.isfile('todo.dat'): with open('todo.dat', 'rb') as fp: todo = pickle.load(fp) else: todo = [] if sys.argv[1] == 'list': for x in enumerate(todo, 1): print('%s: %s' % x) elif sys.argv[1] == 'add': todo.append(sys.argv[2]) elif sys.argv[1] == 'done': todo.pop(int(sys.argv[2]) - 1) with open('todo.dat', 'wb') as fp: pickle.dump(todo, fp)