code: def jaccard(a, b):
      if isinstance(a, dict) and isinstance(b, dict):
          a = a.keys()
          b = b.keys()
      a = set(a)
      b = set(b)
      ans = 1.0 - float(len(a.intersection(b))) / len(a.union(b))
      return ans
  
imports: from __future__ import print_function
  from __future__ import division
  from __future__ import absolute_import
  import copy
  import unittest
  import numpy
  import turicreate
  from turicreate.toolkits._main import ToolkitError
  from collections import Counter
  import sys
label_desc: Use image node_id 1 for calling a global function with example usage: jaccard(a, b) and returns: ans