Python爬虫scrapy从零开始学习杂记（3））
这篇文章讲述的是我学习怎么防止scrapy爬虫被ban的过程~
我所学习和参考的资料链接：
https://www.jianshu.com/p/70d587e8baf2（写这篇杂记时已经使用过了，可行）
http://www.360doc.com/content/17/1213/15/47241897_712718993.shtml
现先详细讲一下自己使用的方法,即轮换User_Agent:
步骤1：打开文件，在setting.py中输入以下内容：
USER_AGENTS = [
"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 Fe2dora/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",
]DOWNLOADER_MIDDLEWARES = {
'hzfangjia.middlewares.HzfangjiaDownloaderMiddleware': 1,
}class RandomUserAgent(object):
def __init__(self, agents):
self.agents = agents
def from_crawler(cls, crawler):
return cls(crawler.settings.getlist('USER_AGENTS'))
def process_request(self, request, spider):
request.headers.setdefault('User-Agent', random.choice(self.agents))步骤3：修改setting.py中的参数：
'''下载延时，即下载两个页面的等待时间'''
DOWNLOAD_DELAY = 0.5
'''并发最大值'''
CONCURRENT_REQUESTS = 100
'''对单个网站并发最大值'''
CONCURRENT_REQUESTS_PER_DOMAIN = 100
'''启用AutoThrottle扩展，默认为False'''
AUTOTHROTTLE_ENABLED = False
'''设置下载超时'''
DOWNLOAD_TIMEOUT = 10
'''降低log级别，取消注释则输出抓取详情'''
LOG_LEVEL = 'INFO'—————写于2018年3月9日星期五 20:03————————
参考文件出处：
原作者：504数据专业处理
链接：https://www.jianshu.com/p/70d587e8baf2
來源：简书
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