Efficient way to find missing elements in an integer sequence

Question

Suppose we have two items missing in a sequence of consecutive integers and the missing elements lie between the first and last elements. I did write a code that does accomp

Answer 1

First we should sort the list and then we check for each element, except the last one, if the next value is in the list. Be carefull not to have duplicates in the list!

l.sort()

[l[i]+1 for i in range(len(l)-1) if l[i]+1 not in l]