Offset positive and negative numbers in two lists and get the rest in Python

Question

I have two lists consisting of a series of positive or negative numbers, and two lists may have unequal lengths, like this:

lst1 = [2, 3, 3, 5, 6, 6, 6, 8, 10]
lst2 = [-1, -2, -2, -3, -6, -10, -11]

The result I want to get is:

lst_ofs = [-1, -2, 3, 5, 6, 6, 8, -11]

Positive and negative numbers with equal absolute value in the two lists are offset by quantity, is there any easy way to do this?

Answer 1

result = lst1 + lst2
# keep checking for pairs until none are left
while True:
    for v in result:
        if -v in result:
            # if v and -v are in the list, remove them both
            # and restart the for loop
            result.remove(v)
            result.remove(-v)
            break
    else:
        # if the for loop made it all the way to the end,
        # break the outer loop
        break

This isn't the most efficient solution, because the for loop starts over each time two values are removed. But it should work.