How do “and” and “or” work when combined in one statement?

Question

For some reason this function confused me:

def protocol(port):
    return port == \"443\" and \"https://\" or \"http://\"

Can somebody expl

Answer 1

It's an old-ish idiom; inserting parentheses to show priority,

(port == "443" and "https://") or "http://"

x and y returns y if x is truish, x if x is falsish; a or b, vice versa, returns a if it's truish, otherwise b.

So if port == "443" is true, this returns the RHS of the and, i.e., "https://". Otherwise, the and is false, so the or gets into play and returns `"http://", its RHS.

In modern Python, a better way to do translate this old-ish idiom is:

"https://" if port == "443" else "http://"