python - 循环出现问题并避免崩溃

Question

我在循环这个程序时遇到了麻烦...我想询问他们是否提供了错误格式的字符串或日期...这是我的代码，我不知道为什么它不起作用。每次我运行它并输入一个字符串时，第一次它会说“哎呀!这不是一个有效的日期。再试一次...”如果用户再次输入错误的输入，它就会崩溃

<小时/>

这是我的代码。

while 1 == 1:
    try:
        birthday = raw_input("Enter your Birth date in MM/DD/YYYY format: ")
        birth_date = datetime.strptime(birthday, '%m/%d/%Y')

     except ValueError:
        print "Oops!  That was not a valid date. Try again..."
        birthday = raw_input("Enter your Birth date in MM/DD/YYYY format: ")
        birth_date = datetime.strptime(birthday, '%m/%d/%Y')

     if (((datetime.today() - birth_date).days)/365.2425) > 110:        
        print "Sorry You are older than 110 year i cannot do that math."

     elif ((datetime.today() - birth_date).days) < 0:
        print "Sorry you entered a date in the furture."

     elif ((datetime.today() - birth_date).days) == 0:
        print "OMG You were just born, tomorrow you will be one day old."
        else:
        print "Age: %d days " % ((datetime.today() - birth_date).days)

这是它显示的错误:

birth_date = datetime.strptime(birthday, '%m/%d/%Y')
  File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/_strptime.py", line 325, in _strptime
    (data_string, format))
ValueError: time data 'ASFA' does not match format '%m/%d/%Y'
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Answer 1

好吧，你没有什么可以捕获 except block 中的错误。你可能想要那个:P

尝试:

while True: #Don't need 1==1, while True works too!
    try:
        birthday = raw_input("Enter your Birth date in MM/DD/YYYY format: ")
        birth_date = datetime.strptime(birthday, '%m/%d/%Y')

     except ValueError:
        print "Oops!  That was not a valid date. Try again..."
        #Because everything else is in an else block, now goes back
        #to start of loop
     else:
        #only happens if no exceptions happen
        if (((datetime.today() - birth_date).days)/365.2425) > 110:        
            print "Sorry You are older than 110 year i cannot do that math."
        #rest of your elif tree goes here, etc, etc.
        else: #I'm valid data! Finally!
            break
birth_date #do your calculations here, outside the loop?