How do microseconds work in a datetime.timedelta?

Question

In the example below - I'm getting a value for seconds that do not match the microseconds. It is baffling me. Can anyone shed a light?

>>> a
datetime.datetime(2019, 9, 13, 21, 47, 46, 837435, tzinfo=<UTC>)
>>> b
datetime.datetime(2019, 9, 13, 21, 47, 54, 724570, tzinfo=<UTC>)
>>> (b-a).microseconds
887135
>>> (b-a).seconds
7
>>> (b-a)
datetime.timedelta(seconds=7, microseconds=887135)

Answer 1

Microseconds is not the delta in microseconds, it is the non-integer reminder in microseconds. The time difference is 7 seconds and 887135 microseconds

Answer 2

I just realized that (ba).seconds is not supposed to the equivalent of (ba).microseconds. The exact time difference here is (ba).seconds + (ba).microseconds.