如何使用Scrapy通过代理进行带有身份验证的互联网连接

Question

我的internet连接是通过带有身份验证的代理进行的，当我试图运行scraoy库以制作更简单的示例时，例如：

scrapy shell http://stackoverflow.com

在您使用XPath选择器请求某些内容之前，一切正常，响应是下一个：

>>> hxs.select('//title')
[<HtmlXPathSelector xpath='//title' data=u'<title>ERROR: Cache Access Denied</title'>]

或者，如果试图运行在项目中创建的任何蜘蛛，则会出现以下错误：

C:\Users\Victor\Desktop\test\test>scrapy crawl test
2012-08-11 17:38:02-0400 [scrapy] INFO: Scrapy 0.16.5 started (bot: test)
2012-08-11 17:38:02-0400 [scrapy] DEBUG: Enabled extensions: LogStats, TelnetCon
sole, CloseSpider, WebService, CoreStats, SpiderState
2012-08-11 17:38:02-0400 [scrapy] DEBUG: Enabled downloader middlewares: HttpAut
hMiddleware, DownloadTimeoutMiddleware, UserAgentMiddleware, RetryMiddleware, De
faultHeadersMiddleware, RedirectMiddleware, CookiesMiddleware, HttpProxyMiddlewa
re, HttpCompressionMiddleware, ChunkedTransferMiddleware, DownloaderStats
2012-08-11 17:38:02-0400 [scrapy] DEBUG: Enabled spider middlewares: HttpErrorMi
ddleware, OffsiteMiddleware, RefererMiddleware, UrlLengthMiddleware, DepthMiddle
ware
2012-08-11 17:38:02-0400 [scrapy] DEBUG: Enabled item pipelines:
2012-08-11 17:38:02-0400 [test] INFO: Spider opened
2012-08-11 17:38:02-0400 [test] INFO: Crawled 0 pages (at 0 pages/min), scraped
0 items (at 0 items/min)
2012-08-11 17:38:02-0400 [scrapy] DEBUG: Telnet console listening on 0.0.0.0:602
4
2012-08-11 17:38:02-0400 [scrapy] DEBUG: Web service listening on 0.0.0.0:6081
2012-08-11 17:38:47-0400 [test] DEBUG: Retrying <GET http://automation.whatismyi
p.com/n09230945.asp> (failed 1 times): TCP connection timed out: 10060: Se produ
jo un error durante el intento de conexi¾n ya que la parte conectada no respondi
¾ adecuadamente tras un periodo de tiempo, o bien se produjo un error en la cone
xi¾n establecida ya que el host conectado no ha podido responder..
2012-08-11 17:39:02-0400 [test] INFO: Crawled 0 pages (at 0 pages/min), scraped
0 items (at 0 items/min)
...
2012-08-11 17:39:29-0400 [test] INFO: Closing spider (finished)
2012-08-11 17:39:29-0400 [test] INFO: Dumping Scrapy stats:
{'downloader/exception_count': 3,
  'downloader/exception_type_count/twisted.internet.error.TCPTimedOutError': 3,
     'downloader/request_bytes': 732,
     'downloader/request_count': 3,
     'downloader/request_method_count/GET': 3,
     'finish_reason': 'finished',
     'finish_time': datetime.datetime(2012, 8, 11, 21, 39, 29, 908000),
     'log_count/DEBUG': 9,
     'log_count/ERROR': 1,
     'log_count/INFO': 5,
     'scheduler/dequeued': 3,
     'scheduler/dequeued/memory': 3,
     'scheduler/enqueued': 3,
     'scheduler/enqueued/memory': 3,
     'start_time': datetime.datetime(2012, 8, 11, 21, 38, 2, 876000)}
2012-08-11 17:39:29-0400 [test] INFO: Spider closed (finished)

看来问题出在我的代理人身上。如果有人知道如何使用带认证代理的scrapy，请告诉我。

Answer 1

重复Mahmoud M.Abdel Fattah的回答，因为该页现在不可用。不过，我还是对他做了些小小的修改。

如果middlewares.py已经存在，请在其中添加以下代码。

class ProxyMiddleware(object):
    # overwrite process request
    def process_request(self, request, spider):
        # Set the location of the proxy
        request.meta['proxy'] = "http://YOUR_PROXY_IP:PORT"

        # Use the following lines if your proxy requires authentication
        proxy_user_pass = "USERNAME:PASSWORD"
        # setup basic authentication for the proxy
        encoded_user_pass = base64.encodestring(proxy_user_pass.encode())
        #encoded_user_pass = base64.encodestring(proxy_user_pass)
        request.headers['Proxy-Authorization'] = 'Basic ' + \
            str(encoded_user_pass)

在settings.py文件中，添加以下代码

    DOWNLOADER_MIDDLEWARES = {
    'project_name.middlewares.ProxyMiddleware': 100,
}

这应该通过设置http_proxy来工作。然而，在我的例子中，我试图用HTTPS协议访问一个URL，需要设置https_proxy，我仍在研究。这方面的任何线索都会有很大帮助。