方式一：在每个 Spider中设置（针对单个Spider）
class TencentSpider(scrapy.Spider): name = 'tencent' allowed_domains = ['hr.tencent.com'] headers = { 'User-Agent': 'Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/63.0.3239.132 Safari/537.36', } def parse(self, response): # 找到最后一页的页码 page_num = response.xpath('//div[@class="pagenav"]/a[last()-1]/text()').extract()[0] # 生成每一页的请求 for i in range(1, int(page_num) + 1): url = "https://hr.tencent.com/position.php?&start=%s#a" % (i * 10) yield Request(url=url, headers=TencentSpider.headers, callback=self.parse)
方式二： 在中间件中设置（全局）
在配置文件中设置User-Agent集合
# 请求头 CUSTOM_USER_AGENT = [ "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", ]
编写中间件逻辑
# 请求头添加随机user-agent class RandomUserAgentMiddleware(object): def __init__(self, agents): self.agent = agents @classmethod def from_crawler(cls, crawler): return cls( agents=crawler.settings.get('CUSTOM_USER_AGENT') ) def process_request(self, request, spider): request.headers.setdefault('User-Agent', random.choice(self.agent))
激活中间件，并禁用默认的User-Agent中间件
DOWNLOADER_MIDDLEWARES = { 'scrapy.downloadermiddleware.useragent.UserAgentMiddleware': None, 'day1.middlewares.RandomUserAgentMiddleware': 10, }
查看请求头信息
响应 response 中封装了请求对应request，因此可以根据request中查看该响应请求时的请求头信息。
def parse(self, response): print(response.request) print(response.request.headers['User-Agent'])
使用 fake-useragent 模块随机生成 User-Agent
上面的user-agent是在配置文件中预先设定好的，我们也可以使用python模块 fake-useragent 生成user-agent
安装：
pip install fake-useragent
简单使用：
from fake_useragent import UserAgent ua = UserAgent() #ie浏览器的user agent print(ua.ie) Mozilla/5.0 (compatible; MSIE 9.0; Windows NT 6.1; Trident/5.0; chromeframe/13.0.782.215)
#opera浏览器 print(ua.opera) #chrome浏览器 print(ua.chrome) #firefox浏览器 print(ua.firefox) #safri浏览器 print(ua.safari) #最常用的方式 #写爬虫最实用的是可以随意变换headers，一定要有随机性。支持随机生成请求头 print(ua.random)
在中间件中使用
import random from scrapy import signals from fake_useragent import UserAgent class RandomUserAgentMiddleware(object): def __init__(self): self.agent = UserAgent() @classmethod def from_crawler(cls, crawler): return cls() def process_request(self, request, spider): request.headers.setdefault('User-Agent', self.agent.random)