How does this print syntax work? print('something', ['a', 'list'][boolean])

Question

print('something', ['a', 'list'][boolean])

Depending on the boolean value this either prints, a or list.

I have never seen this notation before and am wondering how it works.

Answer 1

1. Python's bool is a subclass of int, where True is 1 and False is 0.
   isinstance(True, int) # True
2. As such, booleans can be used as indexes. ['a', 'list'][boolean] evaluates to
   ['a', 'list'][0] if boolean is False or to ['a', 'list'][1] if boolean is True

This can be abused by using conditions directly:

x = 1
print(['no', 'yes'][x > 0])
# yes