python - 如何让程序回到 "menu"？

Question

Done = False
while not Done:
    print('S Start New Order')
    print('E Edit Order')
    print('P Print Bill')
    print('R Receive Payment')
    print('M Manager Report')
    print('Q Quit')
    print('-----------------')

    Command = ''
    while Command == '':
        Command = input("Enter Choice> ")
        Command = Command.strip().upper()
        if Command[0] == 'S':
            print('Start New Order:')     
        elif Command[0] == 'E':
            print('Edit Order:')
        elif Command[0] == 'P':
            print('Print Bill:')
        elif Command[0] == 'R':
            print('Recieve Payment:')
        elif Command[0] == 'M':
            print('Manager Report:')
        elif Command[0] == 'Q':
            print('Quit:')

我想做到这一点，当有人键入“j”或“34”时，它会跳回“输入选择”并且不会再次显示整个菜单。

Answer 1

1. 我们必须检查输入的值。

例如

while Command not in ['S', 'E','P', 'R', 'M', 'Q']:
    Command = raw_input("Enter Choice> ")
    Command = Command.strip().upper()

1. 当用户进入菜单的Q选项时使用break语句。或设置 Done = True
的值

例如

elif Command[0] == 'Q':
    print('Quit:')
    break

或

elif Command[0] == 'Q':
    print('Quit:')
    Done = True