input: Write a function to swap the values of two variables and print the swapped values.
  assert swap_values(5, 10)==(10, 5)
  assert swap_values(0, -1)==(-1, 0)
  assert swap_values(100, 200)==(200, 100)
  assert swap_values(-5, -10)==(-10, -5)
  assert swap_values(0, 0)==(0, 0)
output: def swap_values(a, b):
      a, b = b, a
      return a, b