What does i-(i>0) do in for neighbor in active[i-(i>0):i+1]:

Question

I saw some example python code:

for neighbor in active[i-(i>0):i+1]:

and just curious what i-(i>0) here do?

Answer 1

(i>0) is a condition that is True when i>0 and thus yields 1.

You can think of it also as active[i-{1 if i > 0, else 0}:i+1]:

A good comment by @Mad Physicist: bools are a subclass of int where {True,False} == {1,0}. You can find more on this here

Quote from the link above about this code:

No one would recommend using a boolean result in a numeric context