input: Write a function to swap the values of two variables in Python and print the values after the swap.
  assert swap_values(5, 10)==(10, 5)
  assert swap_values(0, 0)==(0, 0)
  assert swap_values(-3, 3)==(3, -3)
output: def swap_values(a, b):
      a, b = b, a
      return a, b