Question

我目前正在研究Zed Shaw的艰难学习Python。

在exercise 35中，可以找到包含以下行的程序：

def bear_room():
    print "There is a bear here."
    print "The bear has a bunch of honey."
    print "The fat bear is in front of another door."
    print "How are you going to move the bear?"
    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 it now."
            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."

一切都好。但是我想在失去比赛之前给予玩家额外的生存机会和警告。我想出了这个：

def bear_room():
    print "There is a bear here."
    print "There bear has a bunch of honey."
    print "The fat bear is in front of another door."
    print "How are you going to move the bear?"
    bear_moved = False
    bear_moved_again = 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 as moved from the door. You can go through it now."
            bear_moved = True
        elif next == "taunt bear" and bear_moved:
            print "The bear is getting angry. Don't taunt him again."
            bear_moved_again = True    
        elif next == "taunt bear" and bear_moved_again:
            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."

不起作用：我得到的，如果我不止一次地嘲笑熊，那就是：“熊生气了。不要再嘲笑他了。”字符串，一遍又一遍，然而，我希望玩家能够在失败之前只嘲讽动物两次（先移动它，然后第二次得到警告）。你知道为什么吗？

另一个问题：如果bear_moved设置为False（第6行），（第13行）说：

elif next == "taunt bear" and not bear_moved:

不会“而不是”将bear_moved设置为True？

非常感谢任何帮助。

Answer 1

更改行

elif next == "taunt bear" and bear_moved:

到

elif next == "taunt bear" and bear_moved and not bear_moved_again:

行

elif next == "taunt bear" and bear_moved_again:

到

elif next == "taunt bear" and bear_moved and bear_moved_again:

在你的原版中，“elif next ==”taunt bear“和bear_moved：”的句子在“elif next ==”taunt bear“and bear_moved_again”之前进行测试。如果您多次输入“嘲讽熊”，其中一个“elif next ==”嘲讽熊“而不是bear_moved”和“elif next ==”taunt bear“和bear_moved”将始终成立。测试，“elif next ==”taunt bear“和bear_moved_again”将永远不会被拍摄。

Answer 2

问题是，当您嘲笑熊两次时，bear_moved仍为true，因此每次程序处理条件时都会触发elif next == "taunt bear" and bear_moved:行。与bear_moved_again相关的行永远不会在代码中找到它。

如果将以前的分支更改为以下代码，则代码应该起作用：

elif next == "taunt bear" and bear_moved:
    print "The bear is getting angry. Don't taunt him again."
    bear_moved_again = True
    bear_moved = False

在第二个问题中不确定您的意思，但此行中没有变量赋值。它只是检查断言是否是这种情况，而不是改变任何东西。

Answer 3

一种轻松的方式是交换两个elif子句，即

变化

elif next == "taunt bear" and bear_moved:
   print "The bear is getting angry. Don't taunt him again."
   bear_moved_again = True    
elif next == "taunt bear" and bear_moved_again:
   dead("The bear gets pissed off and chews your leg off.")

到

elif next == "taunt bear" and bear_moved_again:
   dead("The bear gets pissed off and chews your leg off.")
elif next == "taunt bear" and bear_moved:
   print "The bear is getting angry. Don't taunt him again."
   bear_moved_again = True

虽然可能不太可读。

Answer 4

你可以让bear_moved成为int并计算熊移动的次数

def bear_room():
    print "There is a bear here."
    print "There bear has a bunch of honey."
    print "The fat bear is in front of another door."
    print "How are you going to move the bear?"
    bear_moved = 0

    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 as moved from the door. You can go through it now."
            bear_moved += 1
        elif next == "taunt bear" and bear_moved == 1:
            print "The bear is getting angry. Don't taunt him again."
            bear_moved += 1   
        elif next == "taunt bear" and bear_moved == 2:
            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."

Python（学习python艰难的练习方式35）

4 个答案: