Разделения списка на несколько равных частей.

s = [1,2,3,4,5,6,7,8,9]

[[1,2], [3,4], [5,6]]

NUM = 3                
s = [1,2,3,4,5,6,7,8,9]
f = []
a = []
c = len(s) / NUM
for x in s:
    if s.index(x) >= c:
        f.append(a)
        a = []
        c *= 2
    a.append(x)
f.append(a)    
print(f)

>>> # в виде обычной функции
>>> def chunks(lst, chunk_size):
...     return [lst[i:i+chunk_size] for i in range(0, len(lst), chunk_size)]
... 
>>> chunks(list(range(10)), 2)
[[0, 1], [2, 3], [4, 5], [6, 7], [8, 9]]
>>> # или в виде генератора
... def chunks(lst, chunk_size):
...     for i in range(0, len(lst), chunk_size):
...             yield lst[i:i+chunk_size]
... 
>>> for i in chunks(list(range(10)), 2):
...     print(i)
... 
[0, 1]
[2, 3]
[4, 5]
[6, 7]
[8, 9]
>>>

>>> def chunks(lst, chunk_count):
...     chunk_size = len(lst) // chunk_count
...     return [lst[i:i+chunk_size] for i in range(0, len(lst), chunk_size)]
... 
>>> chunks([1,2,3,4,5,6,7,8,9,10], 2)
[[1, 2, 3, 4, 5], [6, 7, 8, 9, 10]]

>>> def chunks(lst, count):
...     start = 0
...     for i in range(count):
...             stop = start + len(lst[i::count])
...             yield lst[start:stop]
...             start = stop

In [1]: from itertools import zip_longest
 
In [2]: def chunks(lst, count):
   ...:     n = len(lst) // count
   ...:     return list(x for x in zip_longest(*[iter(lst)] * n))
   ...:
 
In [3]: chunks([1, 2, 3, 4, 5, 6, 7, 8, 9, 10], 3)
Out[3]: [(1, 2, 3), (4, 5, 6), (7, 8, 9), (10, None, None)]