有哪些方法可以从用户输入中解析日期/时间？

Question

class Date:
    def __init__(self, digits):   #digits='10/20/21'
        self.month = digits[:2]  #'10'
        self.day = digits[3:5]   #'20'
        self.year = digits[6:8]  #'21'

    def __str__(self):
        return f"Dated this {self.day} day of {self.month}, 20{self.year}"

def checkday(date):        #add 'st', 'nd', 'rd', or 'th' to day
    if int(date.day) == 1 or int(date.day) == 21 or int(date.day) == 31:
        date.day += 'st'
    elif int(date.day) == 2 or int(date.day) == 22:
        date.day += 'nd'
    elif int(date.day) == 3 or int(date.day) == 23:
        date.day += 'rd'
    else:
        date.day += 'th'

def checkmonth(date):     #get name of month
    date.month = monthdic[date.month]

months = ['Jan', 'Feb', 'Mar', 'Apr', 'May', 'June', 'Jul', 'Aug', 'Sep', 'Oct','Nov', 'Dec']
monthdic = {str(i): month for i, month in zip(range(1,13), months)}

date = Date(input("Enter date (mm/dd/yy):\t"))
checkday(date)
checkmonth(date)

print(date)

几个错误归结为一个我没有想到的问题：

如果是一月：1/12/14将不起作用，因为self.month是1/12/14[:2]

Enter date (mm/dd/yy):  1/12/14
Traceback (most recent call last):
  File "date.py", line 38, in <module>
    checkday(date)
  File "date.py", line 14, in checkday
    if int(date.day) == 1 or int(date.day) == 21 or int(date.day) == 31:
ValueError: invalid literal for int() with base 10: '2/'

如果我求助于01/12/14，这也将不起作用，因为01是'01'，并且monthdic['01']不存在：

Enter date (mm/dd/yy):  01/12/14
Traceback (most recent call last):
  File "date.py", line 39, in <module>
    checkmonth(date)
  File "date.py", line 28, in checkmonth
    date.month = monthdic[date.month]
KeyError: '01'

显然

def __init__(self, digits):
    self.month = digits[:2]
    self.day = digits[3:5]
    self.year = digits[6:8]

不是最好的方法，有哪些好的方法（regex除外）

还有一件事：在__init__内调用checkdate()和checkmonth是否合适

Answer 1

最好使用的方法是分割法。您可以拆分正在输入的与'/'相关的文本。因此，类似1/12/14的东西将变成[1, 12, 14]。剩下的就直截了当了

class Date:
    def __init__(self, digits):
        split = digits.split('/')
        self.month = split[0]
        self.day = split[1]
        self.year = split[2]

    def __str__(self):
        return f"Dated this {self.day} day of {self.month}, {self.year}"

Answer 2

作为@MuhameedJaseemsuggested：split = digits.split('/')和split一起工作。还根据许多人的建议改进了代码。代码现在有点优雅了

class Date:
    def __init__(self, digits):
        self.month, self.day, self.year = digits.split('/')


    def __str__(self):
        return f"Dated this {self.day} day of {self.month}, {self.year}"



def checkday(date):

    if date.day[-1] == '1' and date.day[0] != '1':
        date.day += 'st'

    elif date.day[-1] == '2' and date.day[0] != '1':
        date.day += 'nd'

    elif date.day[-1] == '3' and date.day[0] != '1':
        date.day += 'rd'

    else:
        date.day += 'th'


def checkmonth(date):
    date.month = monthdic[date.month]


months = ['Jan', 'Feb', 'Mar', 'Apr', 'May', 'June', 'Jul', 'Aug', 'Sep', 'Oct','Nov', 'Dec']

monthdic = {str(i): month for i, month in zip(range(1,13), months)}



date = Date(input("Enter date (m/d/y):\t"))
checkday(date)
checkmonth(date)