Possible Duplicate:
Iterate over a python sequence in multiples of n?
How to list elements like: ['abcd', 'efghi'] ?
Using the next:
test = map(chr, range(97, 123))
for i in test:
if len(el) == 2:
break
while len(i) != 4:
i = i + i
el.append(i)
it shows: ['aaaa', 'bbbb'] and it's correct in this case