code: def median(data):
      
  
      if len(data) == 0:
          return None
  
      data = sorted(data)
      return float((data[len(data) // 2] + data[(len(data) - 1) // 2]) / 2.)
docs: Return the median of numeric data, unsing the "mean of middle two" method.
      If ``data`` is empty, ``0`` is returned.
  
      Examples
      --------
  
      >>> median([1, 3, 5])
      3.0
  
      When the number of data points is even, the median is interpolated:
      >>> median([1, 3, 5, 7])
      4.0