Create a python class with the following interface.
def __init__(self, start_url):
"""Returns next advert
Parameter "start_url" is a uri such as:
Fetching url will return zero or more adverts on one or more pages.
Iteration over the object returns the details of the individual adverts as a dict or object. Each result object provides the following information:
url: The url that refers to the advert
price: price of the vehicle
mileage: mileage of the vehicle
transmission: Manual, Automatic, etc.
fuel: Petrol, Diesel, etc.
advertType: Trader or Private
It might be necessary to follow the link to the the individual adverts to retrieve all this information. If so then it should be possible to control this behaviour by means of a boolean flag to the AutoTraderSpider constructor.