How to get the right variable referenced

In the code below I am trying to get the second 'while' statement (while digit_check) to receive the new date from the earlier while_count statement. But it seems to be picking up the original assignment for the user_date variable from the first assignment line.

How can I get the new variable assignment to pass to the second while statement?

Thanks much

def main():

    user_date = raw_input("Enter a date in the format mm/dd/yyyy and press 'Enter'  ")
    count = len(user_date)
    digit = ''
    digit_check = ''

    w开发者_如何学Pythonhile count != 10:
        user_date = raw_input('try again  ')
        count = len(user_date)

    if user_date[0].isdigit() and user_date[1].isdigit() and user_date[3].isdigit()  \
       and user_date[4].isdigit() and user_date[6].isdigit() and user_date[7].isdigit() \
       and user_date[8].isdigit() and user_date[9].isdigit() and user_date[2] == '/' \
       and user_date[5] == '/':
           digit_check = True

    while digit_check != True :
       user_date = raw_input('Not right - try again')

    convert_date(user_date)

    print 'That date is ',convert_date(user_date) + ' ' + user_date[3] + user_date[4] + ',' + user_date[6:]

def convert_date(user_date):

    # Convert date to different format
    month = ''

    if user_date[0] == '0' and user_date[1] == '1':
        month = 'January'
    elif user_date[0] == '0' and user_date[1] == '2':
        month = 'February'
    elif user_date[0] == '0' and user_date[1] == '3':
        month = 'March'
    elif user_date[0] == '0' and user_date[1] == '4':
        month = 'April'
    elif user_date[0] == '0' and user_date[1] == '5':
        month = 'May'
    elif user_date[0] == '0' and user_date[1] == '6':
        month = 'June'
    elif user_date[0] == '0' and user_date[1] == '7':
        month = 'July'
    elif user_date[0] == '0' and user_date[1] == '8':
        month = 'August'
    elif user_date[0] == '0' and user_date[1] == '9':
        month = 'September'
    elif user_date[0] == '1' and user_date[1] == '0':
        month = 'October'
    elif user_date[0] == '1' and user_date[1] == '1':
        month = 'November'
    elif user_date[0] == '1' and user_date[1] == '2':
        month = 'December'

    return month


main()

---

One problem is that you aren't recalculating digit_check here:

while digit_check != True :
   user_date = raw_input('Not right - try again')

This will just go into an infinite loop.

I'd suggest that instead of writing a huge function with many loops and lots of assignments, instead you refactor your code into smaller functions and use simpler logic. For example:

def getDate():
    while True:
        user_date = raw_input('Enter a date')
        if validate(user_date):
             return user_date
        else:
             print 'Error, try again.'

def validate(user_date):
    # etc...

---

Or use the built-in library functions?

import re
import datetime

def getDate(msg="Enter a date in the format mm/dd/yyyy and press 'Enter': ", pat=re.compile(r'(\d{1,2})/(\d{1,2})/(\d{4})$')):
    while True:   # repeat until a valid date is entered
        s = raw_input(msg)            # get input
        match = pat.match(s.strip())  # match against regular expression
        if match:                     # match found?
            m,d,y = match.groups()
            try:
                # parse to date
                return datetime.date(int(y), int(m), int(d))
            except ValueError:
                # parsing failed (month 93 is invalid, etc)
                pass

def main():
    userDate = getDate()
    print('You entered {0}'.format(userDate.strftime('%B %d, %Y')))

if __name__=="__main__":
    main()

---

You aren't recomputing digit_check in that while loop, so it's failing forever, even though user_date is changing. Adding the if block inside the while loop after user_date = raw_input('Not right - try again') fixes it.

That being said, you should definitely make that check a separate function, especially since you'll now be calling it twice instead of once.