input: Write a function to create a Python list comprehension that returns the squared values of a given list. The function should take a list as input and return a new list containing the squared values of each element in the input list.
  assert squared_values([1, 2, 3, 5, 8, 13])==[1, 4, 9, 25, 64, 169]
  assert squared_values([0, -1, -2, -3])==[0, 1, 4, 9]
  assert squared_values([])==[]
output: def squared_values(input_list):
      return [x**2 for x in input_list]