def process_request(self, request, spider):
# Called for each request that goes through the downloader
# middleware.
# Must either:
# - return None: continue processing this request
# - or return a Response object
# - or return a Request object
# - or raise IgnoreRequest: process_exception() methods of
# installed downloader middleware will be called
request.headers['User-Agent'] = random.choice(user_agents) # !! These 2 lines
request.meta['proxy'] = random.choice(proxies) # !! These 2 lines
return None