input: Write a function that takes a list of integers as input and returns the sum of the elements in the list. Return the sum as an integer.
  def sum_list(lst):
    total = 0
    for num in lst:
      total += num
    return total
  
  assert sum_list([1, 2, 3, 4, 5]) == 15
  assert sum_list([0, 0, 0]) == 0
  assert sum_list([-1, -2, -3]) == -6
  assert sum_list([]) == 0
output: def sum_list(lst):
    total = 0
    for num in lst:
      total += num
    return total