code: def median(numbers):
      
  
      # Sort the list and take the middle element.
      n = len(numbers)
      copy = sorted(numbers)
      if n & 1:  # There is an odd number of elements
          return copy[n // 2]
      else:
          return (copy[n // 2 - 1] + copy[n // 2]) / 2.0
docs: Return the median of the list of numbers.
      see: http://mail.python.org/pipermail/python-list/2004-December/294990.html