input: Write a function to get the squared values of a given list using list comprehension. If the list is empty, return an empty list. 
  
  assert squared_list([1, 2, 3, 5, 8, 13])==[1, 4, 9, 25, 64, 169]
  assert squared_list([])==[]
output: def squared_list(lst):
      return [x**2 for x in lst]