is vs in

[bowlofred]

No way to redefine it that I'm aware of.

For container types such as list, tuple, set, frozenset, dict, or collections.deque, the expression x in y is equivalent to any(x is e or x == e for e in y).

Given that, I would just redo your test as the same comprehension, just without the equality test.

>>> item = 1
>>> mylist = [True]
>>> item in mylist
True
>>> any(x is item for x in mylist)
False