code: def ntile(n):
      
      sc = SparkContext._active_spark_context
      return Column(sc._jvm.functions.ntile(int(n)))
docs: Window function: returns the ntile group id (from 1 to `n` inclusive)
      in an ordered window partition. For example, if `n` is 4, the first
      quarter of the rows will get value 1, the second quarter will get 2,
      the third quarter will get 3, and the last quarter will get 4.
  
      This is equivalent to the NTILE function in SQL.
  
      :param n: an integer