input: plaintext
  Write a function to swap the values of two variables in Python.
  assert swap_values(5, 10) == (10, 5)
  assert swap_values(0, -1) == (-1, 0)
  assert swap_values("a", "b") == ("b", "a")
  assert swap_values(True, False) == (False, True)
  assert swap_values([1, 2], [3, 4]) == ([3, 4], [1, 2])
  
output:     
  def swap_values(a, b):
      return b, a
  