代理操作
代理操作
概念：
代理服务器
代理的作用
请求和响应的转发（拦截请求和响应）
代理和爬虫之间的关联是什么？
可以基于代理实现更换爬虫程序请求的ip地址
代理ip的网站
西祠
快代理
www.goubanjia.com
代理精灵：http://http.zhiliandaili.cn/
代理的匿名度
高匿 匿名 透明
类型
http https
代理ip爬取实例1
get或post 都是proxies
proxies={‘协议’：ip端口号}
import requests headers = { 'User-Agent':'Mozilla/5.0 (Windows NT 6.1; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/73.0.3683.86 Safari/537.36', 'Connection':'close' } url = 'https://www.baidu.com/s?ie=UTF-8&wd=ip' page_text = requests.get(url,headers=headers,proxies={'https':'125.87.99.237:22007'}).text with open('./ip.html','w',encoding='utf-8') as fp: fp.write(page_text)
代理ip爬取实例2
'Connection':'close' # 防止卡顿
random.choice
在xpath表达式中不可以出现tbody标签
import requests from lxml import etree headers = { 'User-Agent':'Mozilla/5.0 (Windows NT 6.1; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/73.0.3683.86 Safari/537.36', 'Connection':'close' # 防止卡顿 } #构建一个付费的代理池 import random ips_pool = [] url = 'http://ip.11jsq.com/index.php/api/entry?method=proxyServer.generate_api_url&packid=1&fa=0&fetch_key=&groupid=0&qty=103&time=1&pro=&city=&port=1&format=html&ss=5&css=&dt=1&specialTxt=3&specialJson=&usertype=2' page_text = requests.get(url,headers=headers).text tree = etree.HTML(page_text) ip_list = tree.xpath('//body//text()') for ip in ip_list: dic = {'https':ip} ips_pool.append(dic) url = 'https://www.xicidaili.com/nn/%d' #通用的url模板（不可变） all_ips = [] for page in range(1,5): new_url = format(url%page) page_text = requests.get(new_url,headers=headers,proxies=random.choice(ips_pool)).text tree = etree.HTML(page_text) #在xpath表达式中不可以出现tbody标签 tr_list = tree.xpath('//*[@id="ip_list"]//tr')[1:] for tr in tr_list: ip = tr.xpath('./td[2]/text()')[0] port = tr.xpath('./td[3]/text()')[0] type_ip = tr.xpath('./td[6]/text()')[0] dic = { 'ip':ip, 'port':port, 'type':type_ip } all_ips.append(dic) print(len(all_ips))
cookie操作
爬虫中处理cookie的操作：
手动处理：将cookie写在headers中
自动处理：session对象。
获取session对象：requests.Session()
作用：
session对象和requests对象都可以对指定的url进行请求发送。只不过使用session进行请求发送的过程中如果产生了cookie则cookie会被自动存储在session对象中。
import requests #基于cookie操作的修正 session = requests.Session() #获取saession url = 'https://xueqiu.com/v4/statuses/public_timeline_by_category.json?since_id=-1&max_id=20352188&count=15&category=-1' #将cookie存储到session中，目的是将ｃｏｏｋｉｅ获取存储到ｓｅｓｓｉｏｎ中 session.get('https://xueqiu.com/',headers=headers) # 有cookie的页面 #保证该次请求时携带对应的cookie才可以请求成功 news_json = session.get(url,headers=headers).json() news_json
验证码的识别
使用线上的打码平台进行自动的识别
云打码
超级鹰
注册《用户中心》身份的账户
登陆
创建一个软件
下载示例代码《开发文档》
import requests from hashlib import md5 class Chaojiying_Client(object): def __init__(self, username, password, soft_id): self.username = username password = password.encode('utf8') self.password = md5(password).hexdigest() self.soft_id = soft_id self.base_params = { 'user': self.username, 'pass2': self.password, 'softid': self.soft_id, } self.headers = { 'Connection': 'Keep-Alive', 'User-Agent': 'Mozilla/4.0 (compatible; MSIE 8.0; Windows NT 5.1; Trident/4.0)', } def PostPic(self, im, codetype): """ im: 图片字节 codetype: 题目类型 参考 http://www.chaojiying.com/price.html """ params = { 'codetype': codetype, } params.update(self.base_params) files = {'userfile': ('ccc.jpg', im)} r = requests.post('http://upload.chaojiying.net/Upload/Processing.php', data=params, files=files, headers=self.headers) return r.json() def ReportError(self, im_id): """ im_id:报错题目的图片ID """ params = { 'id': im_id, } params.update(self.base_params) r = requests.post('http://upload.chaojiying.net/Upload/ReportError.php', data=params, headers=self.headers) return r.json() chaojiying = Chaojiying_Client('bobo328410948', 'bobo328410948', '899370') #用户中心>>软件ID 生成一个替换 96001 im = open('a.jpg', 'rb').read() #本地图片文件路径 来替换 a.jpg 有时WIN系统须要// print(chaojiying.PostPic(im,1004)['pic_str']) #验证码识别函数的封装 def transformCode(imgPath,imgType): chaojiying = Chaojiying_Client('bobo328410948', 'bobo328410948', '899370') im = open(imgPath, 'rb').read() return chaojiying.PostPic(im,imgType)['pic_str'] # 模拟登陆 from urllib import request #验证码的识别：将验证码下载到本地然后提交给打吗平台进行识别 main_url = 'https://so.gushiwen.org/user/login.aspx?from=http://so.gushiwen.org/user/collect.aspx' page_text = requests.get(main_url,headers=headers).text tree = etree.HTML(page_text) code_src = 'https://so.gushiwen.org'+tree.xpath('//*[@id="imgCode"]/@src')[0] request.urlretrieve(code_src,'./code.jpg') #识别验证码 code_text = transformCode('./code.jpg',1004) login_url = 'https://so.gushiwen.org/user/login.aspx?from=http%3a%2f%2fso.gushiwen.org%2fuser%2fcollect.aspx' data = { '__VIEWSTATE': '8/BKAQBaZHn7+GP+Kl2Gx43fFO1NI32RMyVae0RyrtFQue3IAhzQKvkml41cIT42Y//OcQccA8AqGYkvB+NFkU43uaHqU69Y0Z1WT3ZRrr4vR+CF7JlBG29POXM=', '__VIEWSTATEGENERATOR': 'C93BE1AE', 'from': 'http://so.gushiwen.org/user/collect.aspx', 'email': 'www.zhangbowudi@qq.com', 'pwd': 'bobo328410948', 'code': code_text, 'denglu': '登录', } print(code_text) page_text = requests.post(login_url,headers=headers,data=data).text with open('./login.html','w',encoding='utf-8') as fp: fp.write(page_text) # 如何捕获动态变化的请求参数 # 通常请情况下动态变化的请求参数都会被隐藏在前台页面源码中 #验证码的识别：将验证码下载到本地然后提交给打吗平台进行识别 main_url = 'https://so.gushiwen.org/user/login.aspx?from=http://so.gushiwen.org/user/collect.aspx' page_text = requests.get(main_url,headers=headers).text tree = etree.HTML(page_text) code_src = 'https://so.gushiwen.org'+tree.xpath('//*[@id="imgCode"]/@src')[0] request.urlretrieve(code_src,'./code.jpg') #解析出动态变化的请求参数 __VIEWSTATE = tree.xpath('//*[@id="__VIEWSTATE"]/@value')[0] __VIEWSTATEGENERATOR = tree.xpath('//*[@id="__VIEWSTATEGENERATOR"]/@value')[0] #识别验证码 code_text = transformCode('./code.jpg',1004) login_url = 'https://so.gushiwen.org/user/login.aspx?from=http%3a%2f%2fso.gushiwen.org%2fuser%2fcollect.aspx' data = { '__VIEWSTATE': __VIEWSTATE, '__VIEWSTATEGENERATOR': __VIEWSTATEGENERATOR, 'from': 'http://so.gushiwen.org/user/collect.aspx', 'email': 'www.zhangbowudi@qq.com', 'pwd': 'bobo328410948', 'code': code_text, 'denglu': '登录', } print(code_text) page_text = requests.post(login_url,headers=headers,data=data).text with open('./login.html','w',encoding='utf-8') as fp: fp.write(page_text) # 处理下cookie s = requests.Session() #验证码的识别：将验证码下载到本地然后提交给打吗平台进行识别 main_url = 'https://so.gushiwen.org/user/login.aspx?from=http://so.gushiwen.org/user/collect.aspx' page_text = s.get(main_url,headers=headers).text tree = etree.HTML(page_text) code_src = 'https://so.gushiwen.org'+tree.xpath('//*[@id="imgCode"]/@src')[0] # request.urlretrieve(code_src,'./code.jpg') code_data = s.get(code_src,headers=headers).content with open('./code.jpg','wb') as fp: fp.write(code_data) #解析出动态变化的请求参数 __VIEWSTATE = tree.xpath('//*[@id="__VIEWSTATE"]/@value')[0] __VIEWSTATEGENERATOR = tree.xpath('//*[@id="__VIEWSTATEGENERATOR"]/@value')[0] #识别验证码 code_text = transformCode('./code.jpg',1004) login_url = 'https://so.gushiwen.org/user/login.aspx?from=http%3a%2f%2fso.gushiwen.org%2fuser%2fcollect.aspx' data = { '__VIEWSTATE': __VIEWSTATE, '__VIEWSTATEGENERATOR': __VIEWSTATEGENERATOR, 'from': 'http://so.gushiwen.org/user/collect.aspx', 'email': 'www.zhangbowudi@qq.com', 'pwd': 'bobo328410948', 'code': code_text, 'denglu': '登录', } print(code_text) page_text = s.post(login_url,headers=headers,data=data).text with open('./login.html','w',encoding='utf-8') as fp: fp.write(page_text)
反爬机制
robots
UA检测
图片懒加载
代理
cookie
验证码
动态变化的请求参数
动态加载的数据
线程池+数据
pool.map(callback,list)
import time from multiprocessing.dummy import Pool import requests from lxml import etree start = time.time() urls = [ 'https://www.huya.com/', 'https://www.huya.com/428354', ] def get_request(url): page_text = requests.get(url).text return page_text def parse(page_text): tree = etree.HTML(page_text) print(tree.xpath('//div[1]//text()')) pool = Pool(2) page_text_list = pool.map(get_request,urls) pool.map(parse,page_text_list) print(len(page_text_list)) print('总耗时：',time.time()-start)
小结：
- 代理 - 代理服务器，拦截请求和响应。来更换请求对应的ip地址。 - get、post(proxies={'http':'ip:port'}) - 如何构建代理池 - cookie： - 手动 - 自动 - session作用 - 模拟登陆 - 验证码 - 模拟登陆的实现流程： - 就是对点击登陆按钮对应的post请求进行发送即可 - post请求一定会携带相关的请求参数 - 动态变化的请求参数：是存在于前台页面源码中 - 线程池： - pool.map(callback,list)
