A simple example would be, instead of doing
for _ in range(_):
print name1
print name2
print value1
print value2
you could do,
values = []
for _ in range(_):
values.append([name1, name2, value1, value2])
For your specified format (and if I understand it correctly), I would do
values = []
for _ in range(_):
if value2 > value1:
values.append([name1, name2, value2 - value1])