input: 
  def sum_list(input_list):
      """
      Takes a list as input and returns the sum of the items in the list.
      
      >>> sum_list([1, 2, 3, 4, 5])
      15
      >>> sum_list([0, 0, 0])
      0
      >>> sum_list([-1, 1, -2, 2])
      0
      """
      total_sum = 0
      for item in input_list:
          total_sum += item
      return total_sum
  
output:     total_sum = 0
      for item in input_list:
          total_sum += item
      return total_sum