python - 如何获得正确的变量引用

Question

在下面的代码中，我试图获取第二个“while”语句(while digital_check)以从之前的 while_count 语句接收新日期。但它似乎从第一个赋值行中获取了 user_date 变量的原始赋值。

如何将新的变量赋值传递给第二个 while 语句？

非常感谢

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 = ''

    while 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()

Answer 1

一个问题是您没有在此处重新计算 digital_check:

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

这将进入无限循环。

我建议不要编写一个包含许多循环和大量赋值的巨大函数，而是将代码重构为更小的函数并使用更简单的逻辑。例如:

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...