I'm trying to remove items from a nested list in Python. I have a nested list as follows: families = [[0, 1, 2],[0, 1, 2, 3],[0, 1, 2, 3, 4],[1, 2, 3, 4, 5],[2, 3, 4, 5, 6]] I want to remove the entries in each sublist that coorespond to the indexed position of the sublist in the master list. So, for example, I need to remove 0 from the first sublist, 1 from second sublist, etc. I am trying to use a list comrehension do do this. This is what I have tried: familiesNew = [ [ families[i][j] for j in families[i] if i !=j ] for i in range(len(families)) ] This works for range(len(families)) up to 3, however beyond that I get IndexError: list index out of range. I'm not sure why. Can somebody give me an idea of how to do this. Preferably a one-liner (list comprehension). Thanks.