Question

我无法在布尔语句后得到正确的逻辑，因此该函数无法运行。

我将代码基于LPTHW练习35。我基本上只是复制了该练习的结构，并试图使其生效。我想测试一下，看看是否可以使while循环正常工作。

如果我在国会大厦Y上键入“是”，它将打印“放在雨衣上，..”，但不会运行函数rain（）。我收到以下错误：

Traceback (most recent call last):
  File "ex35_2.py", line 52, in <module>
    temp ()
  File "ex35_2.py", line 12, in temp
    wool()
  File "ex35_2.py", line 29, in wool
    rain()
TypeError: 'bool' object is not callable

此外，else条件退出程序，我看到了。但是，如果我希望它再次从顶部开始怎么办？它一直循环直到它得到是或否？


def wool():
    print "OK, so it is pretty cold outside!"
    print "Put on the wool."
    print "But is it raining?"
    rain = True

    while True:
        next = raw_input("> ")

        if next == "Yes": #if written with "Yes", it prints "Put on the.." 
            print "Put on the rain coat, m*!" 
            rain()
        elif next == "Yes" and rain:
            print "It is raining, but I dont wanna stress with the rain coat!"
        elif next == "No" and not rain: #how do I activate this condition since rain = True?
            print "You dont need a raincoat."
            march("With wool and no raincoat.")
        else:
            print "You should make a choice." #this is the only output. 
        exit(0)

当我提供其他用户输入时，它直接进入else语句。

You should make a choice.

Answer 1

我假设您在调用rain()函数之前在某个位置加载了模块或定义了函数wool()。

所以，现在发生的事情是，在声明变量rain = True的那一刻本地变量定义优先于先前的函数定义。这意味着，而不是调用函数rain()而是“调用”变量rain。

为了避免这种情况，请确保跟踪您的名称空间。如果导入包含rain的模块，则可以导入整个模块，然后使用module_name.rain()。

如果仅在脚本中定义函数，则需要重命名函数或变量。例如，将rain = True替换为it_is_raining = True

虽然这解释了为什么未调用rain()的原因，但是您还需要注意if ... elif ...构造的顺序。如果输入'Yes'，则将始终在if语句之后执行代码，并且随后的条件将被跳过。

Answer 2

Your program prints out the else-statement, because you haven't indented the content inside your else and elif. Right now, "You should make a choice" is printed outside your if-statement.

Answer 3

I will try to correct the code and give some advice:

def wool():
    print "OK, so it is pretty cold outside!"
    print "Put on the wool."
    print "But is it raining?"
    rain = True

    while True:
        next = raw_input("> ")

        if next == "Yes": #if written with "Yes", it prints "Put on the.." 
            print "Put on the rain coat!" 
            rain()
        elif next == "Yes" and rain: #!!!
            print "It is raining, but I dont wanna stress with the rain coat!" #!!!
        elif next == "No" and not rain: #how do I activate this condition since rain = True?
            print "You dont need a raincoat."
            march("With wool and no raincoat.")
        else:
            print "You should make a choice." #this is the only output. # !!!
        exit(0)

Look for #!!! First one: this elif will never be evaluated, just because if next == "Yes" the first if will win, surely. I would change it to:

if next == "Yes": #if written with "Yes", it prints "Put on the.."
    if rain:
        print "It is raining, but I dont wanna stress with the rain coat!"
    else:
        print "Put on the rain coat, *****!" 
        rain()
elif next .....

Logic behind something here is hidden: you are asking if it's raining, and write down: rain = True

"how do I activate this condition since rain = True?"

well, if user said it's not raining, it's not raining.

I dunno why you are using a pre-setted boolean even if you have user input.

Indentation after else: statement.

Well, you else statement will get every "No" input, because rain is indeed always True.

Thinking that rain boolean is somehow needed:

elif next == "No" 
    if rain:
        print("Lie!")
        #maybe rain = False ??
    else:
        print "You dont need a raincoat."
        march("With wool and no raincoat.")
else:
    print "You should make a choice." #this is the only output. # !!!
exit(0)

无法获得基于布尔语句的while循环以正常运行

3 个答案: