code: def grouper(iterable, n, fillvalue=None):
      """Collect data into fixed-length chunks or blocks.
  
      >>> list(grouper('ABCDEFG', 3, 'x'))
      [('A', 'B', 'C'), ('D', 'E', 'F'), ('G', 'x', 'x')]
  
      """
      if isinstance(iterable, int):
          warnings.warn(
              "grouper expects iterable as first parameter",
              DeprecationWarning,
          )
          n, iterable = iterable, n
      args = [iter(iterable)] * n
      return zip_longest(fillvalue=fillvalue, *args)
  
imports: import warnings
  from collections import deque
  from itertools import chain, combinations, count, cycle, groupby, islice, repeat, starmap, tee, zip_longest
  import operator
  from random import randrange, sample, choice
label_desc: Use image node_id 14 for calling a global function with example usage: grouper(iterable, n, fillvalue) and returns: zip_longest