如何在Python中找到未来时间的纪元时间

Question

I'm currrently writing an alarm clock in Python, However i have some technical difficulties. The user has the option for the alarm to repeat (on given days), or to not repeat. They then provide the minutes and hour at which they want the alarm to trigger.

For my alarm system to work, i need to know the time as an epoch of when the alarm should trigger.

If i am trying to set an alarm, (for example for 19:30, time will always be inputted as 24 hours), i need the alarm to be able to find out the epoch time of the next time it is 19:30, because it could either be on the same day if i set the alarm before 19:30, or it could be for the next day if i set the alarm after 19:30.

Because of this it means i can't simply do time.localtime() , and then take the resulting struct_time object and swap out the hours and minutes to the integers of 19 and 30 (located at indexes 3 and 4 respectively of the object's named tuple), as i would also have to correctly assign the values of the month, day, and day of the year in order to have a valid struct_time object, which, whilst possible, would require a lot of manipulating, when i feel like there is likely a much more reasonable way of doing this.

Any help would be much appreciated

Answer 1

You can simply use the timestamp method on the result. This will return the epoch time of the datetime instance. This will work in almost any circumstance, especially since it is a simple alarm clock, but be aware of this wraning from the docs.

Naive datetime instances are assumed to represent local time and this method relies on the platform C mktime() function to perform the conversion. Since datetime supports wider range of values than mktime() on many platforms, this method may raise OverflowError for times far in the past or far in the future.

Depending on your program architecture you might also consider using the amount of seconds between two times, which can be done using simple subtraction to get a timedelta and the total_seconds function:

import time
import datetime

start = datetime.datetime.now()

time.sleep(2)

end = datetime.datetime.now()

# print total seconds
print((end - start).total_seconds())