Finding the largest absolute difference in a list
A more idiomatic and readable solution would be to use itertools.combinations(list, 2) to take all pairs.

max(abs(a) - abs(b) for a, b in itertools.combinations(int_list, 2))


However, that is O(n2). A smarter O(n) solution would be to subtract the minimum absolute value from the maximum absolute value.

absolutes = [abs(elem) for elem in int_list]
print max(absolutes) - min(absolutes)