Iterate over array twice (cartesian product) but consider only half the elements

Question

I am trying to iterate over an array twice to have pairs of elements (e_i,e_j) but I only want the elements such that i < j.

Basically, what I want would look lik

Answer 1

Can't you just use the range function and go with:

vect = [...]
for i in range(0, len(vect)):
    for j in range(i+1, len(vect)):
        do_something()