code: def mix_generators(generator_list):
    
    i = 0
    l = len(generator_list)
    stopiters_seen = 0
    while stopiters_seen <= l:
      try:
        yield six.next(generator_list[i % l])
        i += 1
        stopiters_seen = 0
      except StopIteration:
        i += 1
        stopiters_seen += 1
docs: Given python generators, generate from one, then from another, etc.