Python：获取嵌套的 while 循环以使用布尔语句（初学者）答案

【问题标题】：Python: getting nested while loops to work with boolean statements(beginner)Python：获取嵌套的 while 循环以使用布尔语句（初学者）
【发布时间】：2012-09-24 01:17:12
【问题描述】：

您好，我是 python 的初学者，我正在尝试创建一个在程序中输入和显示日期的程序

当用户输入超出限制的数字时，我尝试实现循环。为了确定月份，while 循环运行良好：

month = int(input("Which numeric month of the year were you born in?\n"))
while((month <=0) or (month >12)):
    print("The Month must be within the range 12>= Month >0. Please enter the value again.")
    print("\n")
    month = int(input("Which numeric month of the year were you born in?\n"))

但是，对于第二部分（如下），确定日期时，当用户输入限制为 28 天的 2 月份的值时，它显示的循环消息是针对不同的条件（第三个 if day 集合中的语句）代替。

如果您输入：month 为 2，day 为 30。它循环的消息是：

...30

而不是显示：

28

有人可以帮我弄清楚如何正确使用while语句吗？

我的代码如下：

day = int(input("Which numeric day of the month were you born in?\n"))
while(month == 1,3,5,7,8,10,12):
    if(day <=0) or (day >31):
        print("For your selected month, the value for day must be within the range 31>= Day >0. Please enter the value again.")
        print("\n")
        day= int(input("Which numeric day of the month were you born in?\n"))
while(month ==2):
    if(day <=0) or (day >28):
        print("For your selected month, the value for day must be within the range 28>= Day >0. Please enter the value again.")
        print("\n")
        day= int(input("Which numeric day of the month were you born in?\n"))
while(month ==4,6,9,11):
    if(day <=0) or (day >30):
        print("For your selected month, the value for day must be within the range 30>=Day>0. Please enter the value again.")
        print("\n")
        day= int(input("Which numeric day of the month were you born in?\n"))

请注意，我在使用它时仅限于初学者级别的 Python 代码。除此之外，我能做的最多就是使用for 循环而不是while 循环，但没有比这更高级的了。

程序应在程序结束时显示个人的出生日期。

【问题讨论】：

在您解决了 avasal 提出的问题后，我不确定如果满足条件，您的循环是否会中断。所以，如果你有while(int(month)) in [4,6,9,11]:，你看起来好像没有在这里休息。
如果我不使用 in，但大多数情况下都满足，我只是遇到了“while”条件重叠的问题，就像我在问题中解释的那样。
看看glglgl的回答。他很好地解释了while 循环:)

标签： python loops if-statement while-loop boolean

【解决方案1】：

你有太多的while循环。其中一些你永远无法逃脱。

在你知道你有哪个月之后，你应该决定这个月有多少天：

所以你有

month = int(input("Which numeric month of the year were you born in?\n"))
while((month <=0) or (month >12)):
    print("The Month must be within the range 12>= Month >0. Please enter the value again."):
    print("\n")
    month = int(input("Which numeric month of the year were you born in?\n"))
if month in (4, 6, 9, 11): # short
    maxdays = 30
elif month != 2: # not February -> long
    maxdays = 31
else:
    # Here we could ask for the year, determine if the year is divisible by 4, by 100 and by 400 and with this information determie if we have a leap year, but...
    # we are tolerant for now and accept the 29 as well.
    maxdays = 29

现在您可以使用现有的东西，而不必过于频繁地重复自己：

day = int(input("Which numeric day of the month were you born in?\n"))
if(day <= 0) or (day > maxdays):
    print("For your selected month, the value for day must be within the range {0} >= Day > 0. Please enter the value again.".format(maxdays))
    print("\n")
    day = int(input("Which numeric day of the month were you born in?\n"))

如果你还没有学过format()，你可以做

    print("For your selected month, the value for day must be within the range " + str(maxdays) + " >= Day > 0. Please enter the value again.")

甚至

    print("For your selected month, the value for day is wrong. Please enter the value again.")

【讨论】：

@user1716168 他错过了一个报价。