code: def grouper(n, iterable, fillvalue):
      "grouper(3, 'ABCDEFG', 'x') --> ABC DEF Gxx"
      args = [iter(iterable)] * n
      return zip_longest(fillvalue=fillvalue, *args)
  
imports: from itertools import zip_longest
  import numpy
label_desc: Use image node_id 1 for calling a global function with example usage: grouper(n, iterable, fillvalue) and returns: zip_longest