code: def levenshtein(left, right):
      
      sc = SparkContext._active_spark_context
      jc = sc._jvm.functions.levenshtein(_to_java_column(left), _to_java_column(right))
      return Column(jc)
docs: Computes the Levenshtein distance of the two given strings.
  
      >>> df0 = spark.createDataFrame([('kitten', 'sitting',)], ['l', 'r'])
      >>> df0.select(levenshtein('l', 'r').alias('d')).collect()
      [Row(d=3)]