input: 
  def avg_list(lst: List[float]) -> float:
      """ Calculate the average of a list of numbers.
      >>> avg_list([1.0, 2.0, 3.0, 4.0, 5.0])
      3.0
      >>> avg_list([5.5, 6.5, 7.5, 8.5])
      7.0
      """
      sum = 0
      count = 0
      for i in lst:
          sum += i
          count += 1
      avg = sum / count
      return avg
  
output:     sum = 0
      count = 0
      for i in lst:
          sum += i
          count += 1
      avg = sum / count
      return avg