计算两个datetime.time实例之间的timedelta

Question

I'm trying to create a task manager with a spcefic time&task, while the date is irrelevant ( everyday reccurance ).

I'm trying to find the diff between times, eg timedelta(hours=1) :

datetime.time(13,00,00) - datetime.time(14,00,00)

ended with failture:

Traceback (most recent call last):
File "<input>", line 1, in <module>
TypeError: unsupported operand type(s) for -: 'datetime.time' and 'datetime.time'

while datetime.date(2017,06,26) - datetime.date(2017,06,25) ends well.

Answer 1

Python's datetime module doesn't let you calculate time deltas based on time-of-day only. That can result in ambiguities such as what to do when a sum is greater than 24 hours. In your case there is a hack that should work. Turn your times into datetime on the same day and do the math from there.

>>> def time_diff(t1, t2):
...     today = datetime.date.today()
...     return (datetime.datetime.combine(today, t1)
...         - datetime.datetime.combine(today, t2))
... 
>>> 
>>> time_diff(datetime.time(13,0,0), datetime.time(14,0,0))
datetime.timedelta(-1, 82800)

Negative timedelta looks weird (that's -1 days plus 82800 seconds) but should work in other calculations.

Answer 2

要在几秒钟内获得答案，请按如下所示修改您的代码：

return (datetime.datetime.combine(today, t1)-datetime.datetime.combine(today, t2)).total_seconds()