code: def partition_seq(seq, size):
      
      if size < 1:
          raise ValueError('Size must be greater than 0')
      return (seq[pos:pos + size] for pos in xrange(0, len(seq), size))
docs: Splits a sequence into an iterable of subsequences. All subsequences are of the given size,
      except the last one, which may be smaller. If the input list is modified while the returned
      list is processed, the behavior of the program is undefined.
  
      :param seq: the list to split
      :param size: the desired size of the sublists, must be > 0
      :type size: int
      :return: an iterable of sublists
  
      >>> list(partition_seq("",1))
      []
      >>> list(partition_seq("abcde",2))
      ['ab', 'cd', 'e']
      >>> list(partition_seq("abcd",2))
      ['ab', 'cd']
      >>> list(partition_seq("abcde",1))
      ['a', 'b', 'c', 'd', 'e']
      >>> list(partition_seq("abcde",0))
      Traceback (most recent call last):
      ...
      ValueError: Size must be greater than 0
      >>> l=[1,2,3,4]
      >>> i = iter( partition_seq(l,2) )
      >>> l.pop(0)
      1
      >>> next(i)
      [2, 3]