Python program to split a list into two lists with alternating elements

Question

Can you make it more simple/elegant?

def zigzag(seq):
    """Return two sequences with alternating elements from `seq`"""
    x, y = [], []
    p, q = x, y
    for e in seq:
        p.append(e)
        p, q = q, p
    return x, y

Answer 1

def zigzag(seq):
    return seq[::2], seq[1::2]

Answer 2

If seq, as you say, is a list, then:

def zigzag(seq):
  return seq[::2], seq[1::2]

If seq is a totally generic iterable, such as possibly a generator:

def zigzag(seq):
  results = [], []
  for i, e in enumerate(seq):
    results[i%2].append(e)
  return results

Answer 3

This takes an iterator and returns two iterators:

 import itertools
 def zigzag(seq):
     t1,t2 = itertools.tee(seq)
     even = itertools.islice(t1,0,None,2)
     odd = itertools.islice(t2,1,None,2)
     return even,odd

If you prefer lists then you can return list(even),list(odd).