input: Write a function to swap the values of two variables in Python. The function should take two variables as input and return them in swapped order.
  assert swap([5, 10])==[10, 5]
  assert swap(['a', 'b'])==['b', 'a']
  assert swap([3.14, 2.71])==[2.71, 3.14]
  assert swap(['apple', 'orange'])==['orange', 'apple']
  assert swap([1, 1])==[1, 1]
output: def swap(variables):
      return [variables[1], variables[0]]