force_bytes function, use the result as the argument for the call to the hashlib.mdb function, store the result in url. substitute the '%s' in string 'views.decorators.cache.cache_page.%s.%s.%s.%s' with key_prefix, method,
cache_key = 'views.decorators.cache.cache_page.%s.%s.%s.%s' % ( key_prefix , method , url . hexdigest ( ) , ctx . hexdigest ( ) )