Python sched module only works when the time is past otherwise it crashes

Question

When I run this code

import sched,time,webbrowser

def action():
webbrowser.open("https://www.youtube.com/watch?v=dQw4w9WgXcQ")

a = time.strptime('Thu Jan 27 21:25:30 2022')

s = sched.scheduler(time.localtime, time.sleep)
s.enterabs(a, 0,action)
s.run()

it only works when the given time is past the current time if it isn't, I get this error

TypeError: unsupported operand type(s) for -: 'time.struct_time' and 'time.struct_time'

What is causing this problem and how can I solve it?

Answer 1

I usually using this,

https://pypi.org/project/schedule/

and using datetime.isoformat(string) as isoformat datetime.

Answer 2

The scheduler was not designed to work with date+time structures.

From the docs:

timefunc should be callable without arguments, and return a number (the “time”, in any units whatsoever).

You have to switch e.g. to timestamps (number of seconds since some defined start)