Answer by ChaimG for How can I partition (split up, divide) a list based on a condition?

Clear and fast

This list comprehension is simple to read and fast. Exactly what the OP asked for.

set_good_vals = set(good_vals)    # Speed boost.good = [x for x in my_list if x in set_good_vals]bad = [x for x in my_list if x not in set_good_vals]

I would prefer a single list comprehension rather than two, but unlike many of the answers posted (some of which are quite ingenious) it is readable and clear. It is also one of the fastest answers on the page.

The only answer that is [slightly] faster is:

set_good_vals = set(good_vals)good, bad = [], []for item in my_list:    _ = good.append(item) if item in set_good_vals else bad.append(item)

...and variations of this. (See my other answer). But I find the first way more elegant and it's almost as fast.