> policy?.mangle_from_ ?? True
> True (??? since lhs is None?)
>
No, it's not 'policy.mangle_from_' that could be None, it's 'policy'
that could be None (i.e. there's no policy).
In my example, there is a policy, and the value of policy.mangle_from_ is set to None. Thus the above should be equivalent to this
>>> None ?? True
True
Unless, of course, I completely misunderstand the way the ?? operator works. This is not the same as the original code, they are not equivalent.