input: Write a function to improve the efficiency of the given Python code. The given code iterates through a list of numbers and appends to a result list only those values that are greater than 2. The function should return the modified code. If the given input list is empty, the function should return an empty result list.
  assert improve_code("data = [1, 2, 3, 4]\nresult = []\nfor x in data:\n if x > 2:\n result.append(x)")=="data = [1, 2, 3, 4]\n\nresult = [x for x in data if x > 2]"
  assert improve_code("data = []\nresult = []\nfor x in data:\n if x > 2:\n result.append(x)")=='data = []\n\nresult = []'
output: def improve_code(code):
      lines = code.split('\n')
      data_line = lines[0]
      result_line = lines[1]
      data_var = data_line.split('=')[1].strip()
      result_var = result_line.split('=')[1].strip()
      if data_var == '[]':
          return f"{data_line}\n\n{result_var} = []"
      else:
          return f"{data_line}\n\n{result_var} = [x for x in {data_var} if x > 2]"