Question about '|' what it does exactly?

Question

First than anything... Sorry for my poor english.

In an exercise fron here, i have:

A=0
If a|0:
Something x
Else:
Something y

(A|0) what it does??

Answer 1

This is a good overview:

https://www.sololearn.com/learn/4070/?ref=app

Answer 2

Good answer, thanks