def separ(mlist, step, start=0):
    for s in range(start, len(mlist), step):
        print mlist[s:s+step]    
L = range(11)
start = 0
step = 3 
separ(L, step, start)

l = ['a', 'b', 'c', 'a', 'b', 'c', 'a', 'b', 'c']
print zip(*[iter(l)] * 3)

>>> import itertools
>>> 
>>> lst = list('abcdefghij')
>>> list(itertools.zip_longest(*[iter(lst)] * 3))
[('a', 'b', 'c'), ('d', 'e', 'f'), ('g', 'h', 'i'), ('j', None, None)]
>>>

s = iter("1234567")
print map(None, s, s, s)

*[iter(lst)] * 3

k = [None] + [s]*3
print map(*k)

zip(*[iter(l)] * 3)

a = list('123')
b = list("abc")
print zip(a, b)

zip(*[iter(a)] * 3)

zip(*[a] * 3)

[0] * 3

[iter(a)] * 3

a = [1,2,3]
b = [2,3,4]
c = [3,6,7]
rez = zip(a, b, c)

a = [1,2,3]
b = [2,3,4]
c = [3,6,7]
lst = [a, b , c]
rez =zip(*lst)

i = iter(l)
a = i
b = i
c = i
rez = zip(a, b, c)