Skipping elements in a List Python

Question

I\'m new to programming and I\'m trying to do the codingbat.com problems to start. I came across this problem:

Given an array calculate the sum except when there is

Answer 1

I think this is the most compact solution:

def triskaidekaphobicSum(sequence):
    return sum(sequence[i] for i in range(len(sequence))
               if sequence[i] != 13 and (i == 0 or sequence[i-1] != 13))

This uses the builtin sum() function on a generator expression. The generator produces all the elements in the sequence as long as they are not 13, or immediately following a 13. The extra "or" condition is to handle the first item in the sequence (which has no previous item).