Question

bear_moved = False 

while True: 
    next = raw_input("> ") 

    if next == "take honey": 
        dead("The bear looks at you then slaps your face off.") 
    elif next == "taunt bear" and not bear_moved: 
        print "The bear has moved from the door. You can go through." 
        bear_moved = True 
    elif next == "taunt bear" and bear_moved: 
        dead("The bear gets pissed off and chews your leg off.") 
    elif next == "open door" and bear_moved: 
        gold_room() 
    else: 
        print "I got no idea what that means.

这是为了表明我对布尔的理解。在测试next == "taunt bear" and not bear_moved中，如果我的输入为taunt bear，则结果为True and True，这将继续循环。

令我困惑的是线路测试next == "taunt bear" and bear_moved。如果我的输入为taunt bear，那么它是"taunt bear" == "taunt bear"和bear_moved是True and True吗？这意味着循环将继续而不是取消它。

Answer 1

while True:将无限期地继续（除非你输入break - 通常break是像Python这样的语言中的糟糕设计）。

您可能想要这样做：

while something == True: #Or - as has been pointed out, `while something` - which is equivalent and more Pythonic
    ...
    some code which eventually sets something to False
    ...

Answer 2

python中的

elif与else if等效。如果其中一个elif块执行，则其他任何一个都无法执行，并且会跳到if的底部。

执行next == "taunt bear" and not bear_moved并计算为真，并执行该程序后，程序的控制将继续回到循环的前面，并再次请求输入。

真实＆amp; Python中的False布尔值

2 个答案: