Python-以 YYYY-MM-DD 格式将昨天的日期作为字符串获取

作为一个 API 请求的输入，我需要得到昨天的日期作为一个字符串，格式为 YYYY-MM-DD。我有一个工作版本是:

yesterday = datetime.date.fromordinal(datetime.date.today().toordinal()-1)
report_date = str(yesterday.year) + \
('-' if len(str(yesterday.month)) == 2 else '-0') + str(yesterday.month) + \
('-' if len(str(yesterday.day)) == 2 else '-0') + str(yesterday.day)

必须有一个更优雅的方式来做到这一点，感兴趣的教育目的和其他任何事情一样多！

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最佳答案

You Just need to subtract one day from today's date. In Python datetime.timedelta object lets you create specific spans of time as a timedelta object.

datetime.timedelta(1) gives you the duration of "one day" and is subtractable from a datetime object. After you subtracted the objects you can use datetime.strftime in order to convert the result --which is a date object-- to string format based on your format of choice:

>>> from datetime import datetime, timedelta
>>> yesterday = datetime.now() - timedelta(1)


>>> type(yesterday)
>>> datetime.datetime


>>> datetime.strftime(yesterday, '%Y-%m-%d')
'2015-05-26'

Note that instead of calling the datetime.strftime function, you can also directly use strftime method of datetime objects:

>>> (datetime.now() - timedelta(1)).strftime('%Y-%m-%d')
'2015-05-26'

As a function:

from datetime import datetime, timedelta




def yesterday(frmt='%Y-%m-%d', string=True):
yesterday = datetime.now() - timedelta(1)
if string:
return yesterday.strftime(frmt)
return yesterday

example:

In [10]: yesterday()
Out[10]: '2022-05-13'


In [11]: yesterday(string=False)
Out[11]: datetime.datetime(2022, 5, 13, 12, 34, 31, 701270)
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>>> import datetime
>>> datetime.date.fromordinal(datetime.date.today().toordinal()-1).strftime("%F")
'2015-05-26'
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An alternative answer that uses today() method to calculate current date and then subtracts one using timedelta(). Rest of the steps remain the same.

https://docs.python.org/3.7/library/datetime.html#timedelta-objects

from datetime import date, timedelta
today = date.today()
yesterday = today - timedelta(days = 1)
print(today)
print(yesterday)


Output:
2019-06-14
2019-06-13
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Calling .isoformat() on a date object will give you YYYY-MM-DD

from datetime import date, timedelta
(date.today() - timedelta(1)).isoformat()
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I'm trying to use only import datetime based on this answer.

import datetime


oneday = datetime.timedelta(days=1)
yesterday = datetime.date.today() - oneday

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