In Python, 0 == (1 or 0), returns False. Why doesn't it return True? [duplicate]

Question

I'm trying to see if a function returns an integer who's value should be either a 1 or 0.

0 == (1 or 0)

0 is equal to 1 or 0, this sounds like it should be true, but it's not.

Why? And how to do what I'm looking to do correctly?

Answer 1

0 == (1 or 0) is parsed as this tree:

  ==
 /  \
0    or
    /  \
   1    0

1 or 0 results in 1, because or returns the first truthy value of the two operands (and 1 is truthy).

Afterwards, we're left with 0 == 1, which is obviously False.

What you want to do, is check whether 0 is one of those values which you can do through a sequence check: 0 in (0, 1)