168 lines
6.1 KiB
Python
168 lines
6.1 KiB
Python
# Define here the models for your spider middleware
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#
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# See documentation in:
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# https://docs.scrapy.org/en/latest/topics/spider-middleware.html
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from scrapy import signals
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# useful for handling different item types with a single interface
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from itemadapter import is_item, ItemAdapter
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from .myutils import ProxyPool
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from .settings import USERNAME, PASSWORD
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from faker import Faker
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class DecspiderSpiderMiddleware:
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# Not all methods need to be defined. If a method is not defined,
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# scrapy acts as if the spider middleware does not modify the
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# passed objects.
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@classmethod
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def from_crawler(cls, crawler):
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# This method is used by Scrapy to create your spiders.
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s = cls()
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crawler.signals.connect(s.spider_opened, signal=signals.spider_opened)
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return s
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def process_spider_input(self, response, spider):
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# Called for each response that goes through the spider
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# middleware and into the spider.
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# Should return None or raise an exception.
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return None
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def process_spider_output(self, response, result, spider):
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# Called with the results returned from the Spider, after
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# it has processed the response.
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# Must return an iterable of Request, or item objects.
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for i in result:
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yield i
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def process_spider_exception(self, response, exception, spider):
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# Called when a spider or process_spider_input() method
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# (from other spider middleware) raises an exception.
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# Should return either None or an iterable of Request or item objects.
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pass
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def process_start_requests(self, start_requests, spider):
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# Called with the start requests of the spider, and works
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# similarly to the process_spider_output() method, except
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# that it doesn’t have a response associated.
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# Must return only requests (not items).
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for r in start_requests:
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yield r
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def spider_opened(self, spider):
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spider.logger.info("Spider opened: %s" % spider.name)
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class DecspiderDownloaderMiddleware:
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# Not all methods need to be defined. If a method is not defined,
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# scrapy acts as if the downloader middleware does not modify the
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# passed objects.
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@classmethod
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def from_crawler(cls, crawler):
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# This method is used by Scrapy to create your spiders.
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s = cls()
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crawler.signals.connect(s.spider_opened, signal=signals.spider_opened)
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return s
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def process_request(self, request, spider):
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# Called for each request that goes through the downloader
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# middleware.
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# Must either:
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# - return None: continue processing this request
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# - or return a Response object
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# - or return a Request object
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# - or raise IgnoreRequest: process_exception() methods of
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# installed downloader middleware will be called
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return None
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def process_response(self, request, response, spider):
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# Called with the response returned from the downloader.
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# Must either;
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# - return a Response object
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# - return a Request object
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# - or raise IgnoreRequest
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return response
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def process_exception(self, request, exception, spider):
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# Called when a download handler or a process_request()
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# (from other downloader middleware) raises an exception.
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# Must either:
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# - return None: continue processing this exception
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# - return a Response object: stops process_exception() chain
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# - return a Request object: stops process_exception() chain
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pass
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def spider_opened(self, spider):
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spider.logger.info("Spider opened: %s" % spider.name)
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class ProxyMiddleware:
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def __init__(self):
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# 初始化代理列表和每个代理的失败计数
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self.proxy_pool = ProxyPool()
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self.proxy_failures = {proxy: 0 for proxy in self.proxy_pool.proxy_list}
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self.fake = Faker()
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def process_request(self, request, spider):
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# 为每个请求随机选择一个代理
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proxy = self.proxy_pool.get_one()
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if proxy not in self.proxy_failures:
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self.proxy_failures[proxy] = 0
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request.meta['proxy'] = "http://%(user)s:%(pwd)s@%(proxy)s/" % {"user": USERNAME, "pwd": PASSWORD, "proxy": proxy}
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ua = self.fake.user_agent()
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request.headers['User-Agent'] = ua
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spider.logger.info(f'Using proxy: {proxy}\nUsing UA: {ua}')
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def process_response(self, request, response, spider):
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# 如果响应正常，返回响应
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if response.status in [200, 301, 302]:
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return response
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# 如果响应异常，处理失败计数
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else:
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self._handle_proxy_failure(request.meta['proxy'], spider)
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# 重新调度请求
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return request
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def process_exception(self, request, exception, spider):
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# 处理发生异常的请求
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self._handle_proxy_failure(request.meta['proxy'], spider)
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# 重新调度请求
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return request
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def _handle_proxy_failure(self, http_proxy, spider):
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# 增加指定代理的失败计数
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proxy = http_proxy.split('@')[-1][:-1]
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self.proxy_failures[proxy] += 1
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spider.logger.error(f'Proxy {proxy} failed, failure count: {self.proxy_failures[proxy]}')
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# 如果某个代理失败次数达到2次，从列表中移除
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if self.proxy_failures[proxy] >= 2:
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self.proxy_pool.remove(proxy)
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del self.proxy_failures[proxy]
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spider.logger.error(f'Removed proxy {proxy} after consecutive failures.', level=spider.logger.ERROR)
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@classmethod
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def from_crawler(cls, crawler):
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# This method is used by Scrapy to create your spiders.
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s = cls()
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crawler.signals.connect(s.spider_opened, signal=signals.spider_opened)
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return s
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def spider_opened(self, spider):
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spider.logger.info('Spider opened: %s' % spider.name) |