input: def avg_list(lst):
      """Calculate the average of a list of numbers.
      >>> avg_list([1, 2, 3, 4, 5])
      3.0
      >>> avg_list([10, 20, 30])
      20.0
      """
      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