input: def avg_list(lst: List[float]) -> float:
      """
      Calculate the average of a given list of numbers.
      
      >>> avg_list([1.0, 2.0, 3.0, 4.0, 5.0])
      3.0
      >>> avg_list([0.0, 0.0, 0.0])
      0.0
      """
      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
      if count == 0:
          return 0.0
      avg = sum / count
      return avg