new_contents: """
  >>> from pyspark.context import SparkContext
  >>> sc = SparkContext('local', 'test')
  >>> b = sc.parallelize([1, 2, 3, 4])
  >>> basicAvg(b)
  2.5
  """
  
  import sys
  
  from pyspark import SparkContext
  
  def basicAvg(nums):
      """Compute the avg"""
      sumCount = nums.map(lambda x: (x,1)).fold((0, 0), (lambda x, y: (x[0] + y[0], x[1] + y[1])))
      return sumCount[0] / float(sumCount[1])
  
  if __name__ == "__main__":
      master = "local"
      if len(sys.argv) == 2:
          master = sys.argv[1]
      sc = SparkContext(master, "Sum")
      nums = sc.parallelize([1, 2, 3, 4])
      avg = basicAvg(nums)
      print avg
  
  
subject: Add a basic avg example