Processing of Booleans in Python

Question

I have a question about a logical expression of the following sort:

for i in range (k): #k is large
    if (a==b and test(c)==b): #test() takes some time to calculate
         do something

Now I want to know, how the logical expression is processed. Are the two simple expressions calculated first and then combined via and? Or is a==b calculated, and in case it is False, test(c)==b neglected?

Thanks.

Yes, `and` short-circuits and the second expression is not evaluated if the first produced false. — Martijn Pieters, May 19 '17 at 08:35
Check out this Question on SO http://stackoverflow.com/questions/2580136/does-python-support-short-circuiting — Ludisposed, May 19 '17 at 08:37

score 2 · Answer 1 · answered May 19 '17 at 08:35

2

The a==b will be calculated first, and if it's true then the second expression will be evaluated. This is known as 'short-circuiting', see the docs.

answered May 19 '17 at 08:35

Duncan WP

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Processing of Booleans in Python

1 Answers1