code: def median(arr):
    
    if len(arr) == 0:
      sys.stderr.write("ERROR: no content in array to take average\n")
      sys.exit()
    if len(arr) == 1: return arr[0]
    quot = len(arr)/2
    rem = len(arr)%2
    if rem != 0:
      return sorted(arr)[quot]
    return float(sum(sorted(arr)[quot-1:quot+1]))/float(2)
docs: median of the values, must have more than 0 entries.
  
    :param arr: list of numbers
    :type arr: number[] a number array
    :return: median
    :rtype: float