Does python stop verification on first wrong condition in "if and" or does it check it all before deciding?

Question

I have multiple expensive condition to make and I am wondering if this:

if False and False and True and False:
    print("you will never see this")

is longer than this in time computing:

if False:
    if False:
        if True:
            if False:
                print("you will never see this")

Will python stop the first time it see a wrong condition or will it compute every verification before deciding ?

Python evaluates that *lazily*, although given that you have hard-coded conditions it all has to be *parsed* anyway. But e.g. `foo() and bar()` won't call bar if foo returns false-y. — jonrsharpe, Jan 06 '21 at 11:11

score 1 · Accepted Answer · answered Jan 06 '21 at 11:11

1

It doesn't matter, because Python supports short-circuit evaluation:

answered Jan 06 '21 at 11:11

Johan

Thanks for your answers, sorry for the duplicate, I didn't find the rights keywords. (but I think these keywords can still be useful). So the answer is "yes Python stop at the first wrong condition". – Jan 06 '21 at 11:15

1 Answers1