Policy persistence across instances

[kmharrington]

I ran into a strange (to me) error while trying to generate a large batch of schedules yesterday and I don't understand why the behavior of the code worked like it did.

Pseudo code:

from schedlib.policies.satp2 import SATP2Policy

policy = SATP2Policy.from_defaults( ... )
for target in first_targets:
    policy.add_cal_target(**target)

...
go build a schedule file
...

policy = SATP2Policy.from_defaults( ... )
for target in other_targets:
    policy.add_cal_target(**target)

...
build a different schedule file
...

The problem is, when I went to look at the second policy instance, it already had all the first_targets associated with it. Why? The from_defaults method defaults to an empty calibration target list. Also, my actual code that the two policies being generated in two separate function calls so they shouldn't have even been in the same namespace.