如何将字符串还原为命令？

def restore_command(string):
    # 解析字符串，提取指令和参数
    command_parts = string.strip().split(' ')
    command = command_parts[0]
    args = command_parts[1:]

    # 根据指令执行对应的操作
    if command == 'print':
        return ' '.join(args)
    elif command == 'add':
        num1 = int(args[0])
        num2 = int(args[1])
        return str(num1 + num2)
    elif command == 'multiply':
        num1 = int(args[0])
        num2 = int(args[1])
        return str(num1 * num2)
    else:
        return '未知指令'

# 示例用法
command_str = 'print Hello, world!'
restored_command = restore_command(command_str)
print(restored_command)
# 输出：Hello, world!

command_str = 'add 2 3'
restored_command = restore_command(command_str)
print(restored_command)
# 输出：5

command_str = 'multiply 4 5'
restored_command = restore_command(command_str)
print(restored_command)
# 输出：20