input: Write a function to swap the values of two variables in Python. Use a tuple assignment to achieve this.
  assert swap_values(5, 10) == (10, 5)
  assert swap_values(100, 200) == (200, 100)
  assert swap_values(-3, 3) == (3, -3)
  assert swap_values(0, 0) == (0, 0)
  assert swap_values('a', 'b') == ('b', 'a')
output: def swap_values(a, b):
      return (b, a)