input: Write a function to improve the efficiency of the given Python code snippet. The function should replace the for loop and if condition with a more efficient list comprehension. The function should take a list as an input and return the filtered list. If the input list is empty, the function should return an empty list.
  assert improve_efficiency_code([1, 2, 3, 4])==[3, 4]
  assert improve_efficiency_code([1, 2, 3, 4, 5, 6])==[3, 4, 5, 6]
  assert improve_efficiency_code([1, 2])==[]
  assert improve_efficiency_code([])==[]
output: def improve_efficiency_code(lst):
      return [x for x in lst if x > 2] if lst else []