a = [3, 5, 2]
resultado = []
for ix, x in enumerate(a):
for y in a[ix+1:]:
resultado.append(y - x)
print resultado
YSA9IFszLCA1LCAyXQoKcmVzdWx0YWRvID0gW10KCmZvciBpeCwgeCBpbiBlbnVtZXJhdGUoYSk6CiAgICBmb3IgeSBpbiBhW2l4KzE6XToKICAgICAgICByZXN1bHRhZG8uYXBwZW5kKHkgLSB4KQoKcHJpbnQgcmVzdWx0YWRv