問題描述：

在middleware中使用ip代理的時候，報錯如下

2019-01-05 21:16:15 [scrapy.core.scraper] ERROR: Error downloading <GET http://httpbin.org/ip>
Traceback (most recent call last):
  File "e:\anaconda3\lib\site-packages\twisted\internet\defer.py", line 1416, in _inlineCallbacks
    result = result.throwExceptionIntoGenerator(g)
  File "e:\anaconda3\lib\site-packages\twisted\python\failure.py", line 491, in throwExceptionIntoGenerator
    return g.throw(self.type, self.value, self.tb)
  File "e:\anaconda3\lib\site-packages\scrapy\core\downloader\middleware.py", line 43, in process_request
    defer.returnValue((yield download_func(request=request,spider=spider)))
  File "e:\anaconda3\lib\site-packages\scrapy\utils\defer.py", line 45, in mustbe_deferred
    result = f(*args, **kw)
  File "e:\anaconda3\lib\site-packages\scrapy\core\downloader\handlers\__init__.py", line 65, in download_request
    return handler.download_request(request, spider)
  File "e:\anaconda3\lib\site-packages\scrapy\core\downloader\handlers\http11.py", line 67, in download_request
    return agent.download_request(request)
  File "e:\anaconda3\lib\site-packages\scrapy\core\downloader\handlers\http11.py", line 331, in download_request
    method, to_bytes(url, encoding='ascii'), headers, bodyproducer)
  File "e:\anaconda3\lib\site-packages\scrapy\core\downloader\handlers\http11.py", line 252, in request
    proxyEndpoint = self._getEndpoint(self._proxyURI)
  File "e:\anaconda3\lib\site-packages\twisted\web\client.py", line 1635, in _getEndpoint
    return self._endpointFactory.endpointForURI(uri)
  File "e:\anaconda3\lib\site-packages\twisted\web\client.py", line 1513, in endpointForURI
    raise SchemeNotSupported("Unsupported scheme: %r" % (uri.scheme,))
twisted.web.error.SchemeNotSupported: Unsupported scheme: b''
 

middleware程式碼如下：

class IpProxyDownloaderMiddleware(object):
    def __init__(self):
        self.proxy_list = [
            "39.137.107.98:80",
            "111.177.190.124:9999",
            "175.25.26.184:10800"
        ]

    def process_request(self, request, spider):
        proxy = random.choice(self.proxy_list)
        # print("proxy:", proxy)
        request.meta["proxy"] = proxy
 

settings檔案：

# Enable or disable downloader middlewares
# See https://doc.scrapy.org/en/latest/topics/downloader-middleware.html
DOWNLOADER_MIDDLEWARES = {
   'Useragent.middlewares.UseragentDownloaderMiddleware': 543,
   'Useragent.middlewares.IpProxyDownloaderMiddleware': 300,
}

原因分析：

在middleware中代理ip並沒有加"https://" 

因為我用的都是高匿代理所以都需要加https，修改後程式碼：

class IpProxyDownloaderMiddleware(object):
    def __init__(self):
        self.proxy_list = [
            "39.137.107.98:80",
            "111.177.190.124:9999",
            "175.25.26.184:10800"
        ]

    def process_request(self, request, spider):
        proxy = random.choice(self.proxy_list)
        # print("proxy:", proxy)
        request.meta["proxy"] = "https://" + proxy

重新執行，成功！！