这可能会帮助一些人，用这个方法找到过期与否其计算天数。这是dt。秒和dt。微秒也可用

from datetime import datetime
# updated_at = "2022-10-20T07:18:56.950563"
def is_expired(updated_at):
    expires_in = 7 #days
    datetime_format = '%Y-%m-%dT%H:%M:%S.%f'
    time_difference = datetime.now() - datetime.strptime(updated_at, datetime_format)

    return True if time_difference.days > expires_in else False

我用的是这样的:

from datetime import datetime

def check_time_difference(t1: datetime, t2: datetime):
    t1_date = datetime(
        t1.year,
        t1.month,
        t1.day,
        t1.hour,
        t1.minute,
        t1.second)

    t2_date = datetime(
        t2.year,
        t2.month,
        t2.day,
        t2.hour,
        t2.minute,
        t2.second)

    t_elapsed = t1_date - t2_date

    return t_elapsed

# usage 
f = "%Y-%m-%d %H:%M:%S+01:00"
t1 = datetime.strptime("2018-03-07 22:56:57+01:00", f)
t2 = datetime.strptime("2018-03-07 22:48:05+01:00", f)
elapsed_time = check_time_difference(t1, t2)

print(elapsed_time)
#return : 0:08:52

我利用时差进行了连续集成测试，以检查和完善我的功能。如果有人需要，这里有一些简单的代码

from datetime import datetime

class TimeLogger:
    time_cursor = None

    def pin_time(self):
        global time_cursor
        time_cursor = datetime.now()

    def log(self, text=None) -> float:
        global time_cursor

        if not time_cursor:
            time_cursor = datetime.now()

        now = datetime.now()
        t_delta = now - time_cursor

        seconds = t_delta.total_seconds()

        result = str(now) + ' tl -----------> %.5f' % seconds
        if text:
            result += "   " + text
        print(result)

        self.pin_time()

        return seconds


time_logger = TimeLogger()

使用:

from .tests_time_logger import time_logger
class Tests(TestCase):
    def test_workflow(self):
    time_logger.pin_time()

    ... my functions here ...

    time_logger.log()

    ... other function(s) ...

    time_logger.log(text='Tests finished')

我在log输出中有类似的东西

2019-12-20 17:19:23.635297 tl -----------> 0.00007
2019-12-20 17:19:28.147656 tl -----------> 4.51234   Tests finished

这是为了找出当前时间和上午9:30之间的差值

t=datetime.now()-datetime.now().replace(hour=9,minute=30)

Python 2.7新增了timedelta实例方法.total_seconds()。在Python文档中，这相当于(td。微秒+ (td。秒+ td。天* 24 * 3600)* 10**6)/ 10**6。

参考:http://docs.python.org/2/library/datetime.html # datetime.timedelta.total_seconds

>>> import datetime
>>> time1 = datetime.datetime.now()
>>> time2 = datetime.datetime.now() # waited a few minutes before pressing enter
>>> elapsedTime = time2 - time1
>>> elapsedTime
datetime.timedelta(0, 125, 749430)
>>> divmod(elapsedTime.total_seconds(), 60)
(2.0, 5.749430000000004) # divmod returns quotient and remainder
# 2 minutes, 5.74943 seconds

如果a, b是datetime对象，那么在Python 3中查找它们之间的时间差:

from datetime import timedelta

time_difference = a - b
time_difference_in_minutes = time_difference / timedelta(minutes=1)

在早期的Python版本中:

time_difference_in_minutes = time_difference.total_seconds() / 60

如果a, b是天真的datetime对象，例如datetime.now()返回的，那么如果对象表示具有不同UTC偏移量的本地时间，例如DST转换前后或过去/未来日期，则结果可能是错误的。更多细节:查找datetimes之间是否已经过了24小时- Python。

要获得可靠的结果，请使用UTC时间或时区感知的datetime对象。