Finding the largest absolute difference in a list

I'm moving away from map, reduce and filter in favour of list comprehensions. I like list comps but I feel like this is getting on the unreadable side.

Is this the most idiomatic way of achieving this? Is it easy enough to read?

int_list = [-1,-3,5,7]

absolute_diffs = [max( [abs( int_2 ) - abs( int_1 ) for int_2 in int_list] ) for int_1 in int_list]

print max( absolute_diffs )

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)

StackExchange Code Review Q#131764, answer score: 6