Python - datetime - 检查用户输入日期是否与格式匹配答案

【问题标题】：Python - datetime - Check if user input date matches formatPython - datetime - 检查用户输入日期是否与格式匹配
【发布时间】：2022-01-08 17:52:34
【问题描述】：

导入的日期时间，我想验证用户输入的日期以查看它是否与 YYYY-MM-DD 匹配。如果没有，请 print('Sorry wrong format, try again!') 并要求他们再次输入日期。如果他们确实采用了正确的格式，则功能会继续向用户提出下一个问题。现在，我的代码拒绝所有日期格式（即使是正确的）。最终希望将验证函数放在一个单独的函数中，这样它就更干净了。

def add_new_entry(entries):
    
  date = input('When was the transaction? (YYYY-MM-DD): ')
    try:
      transaction_date = datetime.datetime.strptime(date, "%Y/%m/%D")  
    except ValueError:
      print("Sorry, that is in the incorrect format. Try again!")
      return add_new_entry(date)
    transaction = input('Was it Income or Expense? ')
    amount = input('What was the dollar amout? $')
    note = input('Describe the transaction: ')

【问题讨论】：

尝试用"%Y/%m/%d"替换"%Y/%m/%D"
输入提示信息有破折号，但你的格式字符串有斜杠。

标签： python error-handling

【解决方案1】：

日期格式不正确。应该是%Y-%m-%d。 Documentation of the strftime() and strptime() Format Codes

import datetime


def add_new_entry():
    date = input('When was the transaction? (YYYY-MM-DD): ')
    try:
        transaction_date = datetime.datetime.strptime(date, "%Y-%m-%d")
    except ValueError:
        print("Sorry, that is in the incorrect format. Try again!")
        return add_new_entry()
    transaction = input('Was it Income or Expense? ')
    amount = input('What was the dollar amount? $')
    note = input('Describe the transaction: ')
    return date, transaction, amount, note


print(add_new_entry())

输出：

When was the transaction? (YYYY-MM-DD): 2022-01-69
Sorry, that is in the incorrect format. Try again!
When was the transaction? (YYYY-MM-DD): 2022-23-32
Sorry, that is in the incorrect format. Try again!
When was the transaction? (YYYY-MM-DD): 2022-01-08
Was it Income or Expense? Income
What was the dollar amount? $2222
Describe the transaction: Salary
('2022-01-08', 'Income', '2222', 'Salary')

说明：

在执行except 块时，我已删除参数date，因为我假设您想让用户重新输入日期。

参考资料：

Documentation of the strftime() and strptime() Format Codes

【讨论】：