I have some elements in a list in one class. I want them sorted in a new list, and they have to be sorted by an attribute from another class. 

Can anyone give an example?

My code so far looks like this:

```
class Carcompany:
  def __init__(self, model, production_number):
    self.model = model
    self.production_number = production_number
    self.car_list = []

  def add_car_to_car_list(self, car):
    self.car_list.append(car)

class Info:
  def __init__(self):
    self.license_plate_number = []

  def add_license_plate_to_list(self, license_plate):
    self.license_plate_number.append(license_plate)

```

I need `self.car_list` to be sorted by `self.license_plate_number` - highest number first. I don't know how much I'm missing to get there. I appreciate any help I can get :)