Time difference between set.discard and set.remove methods in Python?

Question

The official Python 2.7 docs for these methods sound almost the same, with the only difference being that remove () raises a KeyError and then doesn’t.

I am wondering if there is a difference in execution speed between the two methods. Otherwise, is there any significant difference (KeyError ban) between them?

Answer 1

Raising the exception in one case is a pretty significant difference. If you are trying to remove an element from a set that is not there, there will be an error, it is better to use set.remove() rather than set.discard() .

Both methods are identical in implementation, except that, compared to set_discard() function adds strings:

 if (rv == DISCARD_NOTFOUND) { set_key_error(key); return NULL; } 

A KeyError occurs. Since this is a bit more work, set.remove() is the lower faction slower; Your processor must perform one additional test before returning. But if your algorithm is dependent on an exception, then an additional branching test is unlikely to matter.