I haven't yet fully adjusted to the walrus operator, but to me the choice would ...

I haven't yet fully adjusted to the walrus operator, but to me the choice would depend on what happens _after_ the "if" statement.

In both cases, "foo" continues to exist after the "if" even though the second example makes it look like "foo" is scoped to the "if".

So to my eye, the following would look super weird (assume do_more_stuff can take None):

    if foo := one_or_none():
        do_stuff(foo)
    do_more_stuff(foo)

whereas the following would look fine:

    foo = one_or_none()
    if foo:
        do_stuff(foo)
    do_more_stuff(foo)