code: def difference(seq1, seq2):
      r"""
      Returns all elements in seq1 which are not in seq2: i.e ``seq1\seq2``.
  
      """
      try:
          # try to use O(const * len(seq1)) algo
          if len(seq2) < 4:  # I'm guessing this threshold -JB
              raise Exception("not worth it")
          set2 = set(seq2)
          return [x for x in seq1 if x not in set2]
      except Exception:
          # maybe a seq2 element is not hashable
          # maybe seq2 is too short
          # -> use O(len(seq1) * len(seq2)) algo
          return [x for x in seq1 if x not in seq2]
  
imports: import hashlib
  import logging
  import os
  import struct
  import subprocess
  import sys
  from collections import OrderedDict
  from collections.abc import Callable
  from functools import partial
label_desc: Use image node_id 12 for calling a global function with example usage: difference(seq1, seq2) and returns: unknown, unknown