scrapy动态user-agent

超、凢脫俗 2021-12-15 01:11 248阅读 0赞

scrapy默认的user-agent类似：

User-Agent: b'Scrapy/1.6.0 (+https://scrapy.org)'

一般会自己设置动态user-agent，预防被反爬。步骤：

1、修改setting.py

USER_AGENTS = [
        'Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/75.0.3770.100 Safari/537.36',
        "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; SV1; AcooBrowser; .NET CLR 1.1.4322; .NET CLR 2.0.50727)",
        "Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 6.0; Acoo Browser; SLCC1; .NET CLR 2.0.50727; Media Center PC 5.0; .NET CLR 3.0.04506)",
        "Mozilla/4.0 (compatible; MSIE 7.0; AOL 9.5; AOLBuild 4337.35; Windows NT 5.1; .NET CLR 1.1.4322; .NET CLR 2.0.50727)",
        "Mozilla/5.0 (Windows; U; MSIE 9.0; Windows NT 9.0; en-US)",
        "Mozilla/5.0 (compatible; MSIE 9.0; Windows NT 6.1; Win64; x64; Trident/5.0; .NET CLR 3.5.30729; .NET CLR 3.0.30729; .NET CLR 2.0.50727; Media Center PC 6.0)",
        "Mozilla/5.0 (compatible; MSIE 8.0; Windows NT 6.0; Trident/4.0; WOW64; Trident/4.0; SLCC2; .NET CLR 2.0.50727; .NET CLR 3.5.30729; .NET CLR 3.0.30729; .NET CLR 1.0.3705; .NET CLR 1.1.4322)",
        "Mozilla/4.0 (compatible; MSIE 7.0b; Windows NT 5.2; .NET CLR 1.1.4322; .NET CLR 2.0.50727; InfoPath.2; .NET CLR 3.0.04506.30)",
        "Mozilla/5.0 (Windows; U; Windows NT 5.1; zh-CN) AppleWebKit/523.15 (KHTML, like Gecko, Safari/419.3) Arora/0.3 (Change: 287 c9dfb30)",
        "Mozilla/5.0 (X11; U; Linux; en-US) AppleWebKit/527+ (KHTML, like Gecko, Safari/419.3) Arora/0.6",
        "Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.8.1.2pre) Gecko/20070215 K-Ninja/2.1.1",
        "Mozilla/5.0 (Windows; U; Windows NT 5.1; zh-CN; rv:1.9) Gecko/20080705 Firefox/3.0 Kapiko/3.0",
        "Mozilla/5.0 (X11; Linux i686; U;) Gecko/20070322 Kazehakase/0.4.5",
        "Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.9.0.8) Gecko Fedora/1.9.0.8-1.fc10 Kazehakase/0.5.6",
        "Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/535.11 (KHTML, like Gecko) Chrome/17.0.963.56 Safari/535.11",
        "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_7_3) AppleWebKit/535.20 (KHTML, like Gecko) Chrome/19.0.1036.7 Safari/535.20",
        "Opera/9.80 (Macintosh; Intel Mac OS X 10.6.8; U; fr) Presto/2.9.168 Version/11.52",
        "Mozilla/5.0 (Windows NT 6.1; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/58.0.3029.110 Safari/537.36",
    ]

2、middlewares.py添加class：

class MyspidertestDownloaderMiddleware(object):
    
        def __init__(self, agents):
            # super(MyspidertestDownloaderMiddleware, self).__init__()
            self.agents = agents
    
        # 从crawler构造，USER_AGENTS定义在crawler的配置的设置中
        @classmethod
        def from_crawler(cls, crawler):
            return cls(agents=crawler.settings.get('USER_AGENTS'))
    
        def process_request(self, request, spider):
            # print("-----------" + str(random.choice(self.agents)))
            # 设置随机的User-Agent
            request.headers['User-Agent'] = random.choice(self.agents)
            # 下面的语法设置user-agent没起作用
            # request.headers.setdefault('User-Agent', random.choice(self.agents))
    
        def process_response(self, request, response, spider):
            spider.logger.info('*****************User-Agent: %s' % request.headers["User-Agent"])
            return response
    
        def process_exception(self, request, exception, spider):
            pass
    
        def spider_opened(self, spider):
            spider.logger.info('Spider opened: %s' % spider.name)

3、setting.py修改中间件设置：

DOWNLOADER_MIDDLEWARES = {
        'scrapy.downloadermiddleware.useragent.UserAgentMiddleware': None,
        'mySpiderTest.middlewares.MyspidertestDownloaderMiddleware': 900
    }

通过以上步骤，scrapy动态选择user-agent就完成了。

另外一种方式是fake\_useragent这个第三方库。