Step to reproduce:
Open page: https://docs.python.org/3/library/sched.html

Location: Documentation : sched — Event scheduler 

Description:
In the text is definition of priority: "Events scheduled for the same time will be executed in the order of their priority. A lower number represents a higher priority."

I assume it is correct, but example shows different behavior. There are scheduled two events with priority two and one. In print on the end of example, they are in wrong order :
Code:
s.enter(5, 2, print_time, argument=('positional',))
s.enter(5, 1, print_time, kwargs={'a': 'keyword'}) 

Current Result:
From print_time 930343695.274 positional
From print_time 930343695.275 keyword

Expected result:
From print_time 930343695.274 keyword
From print_time 930343695.275 positional

Conclusion :
I tested the example code and it gave me expected result in order "keyword","positional"