爬虫——requests.get爬虫模块参数
- 2019 年 10 月 3 日
- 笔记
地址和请求头参数–url和header
res = requests.get(url,headers=headers) 向网站发起请求，并获取响应对象
参数
- url ：需要抓取的URL地址
- headers : 请求头
- timeout : 超时时间，超过时间会抛出异常
响应对象(res)属性
- encoding ：响应字符编码 res.encoding = ‘utf-8’
- text ：字符串 网站源码
- content ：字节流 字符串网站源码
- status_code ：HTTP响应码
- url ：实际数据的URL地址
import requests url = 'http://www.baidu.com/' # 爬取百度网页 headers = {'User-Agent': 'Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/535.1 (KHTML, like Gecko) Chrome/14.0.835.163 Safari/535.1'} res = requests.get(url, headers=headers) print(res.encoding) # 查看网站的编码格式 ISO-8859-1 # text属性获取响应内容（字符串）网站源码 res = requests.get(url,headers=headers) res.encoding = 'utf-8' html = res.text # content属性获取响应内容（字节串 bytes）网站源码 res = requests.get(url,headers=headers) html = res.content.decode('utf-8') print(res.status_code) # 查看响应码 200 print(res.url) # 查看访问的URL地址 https://www.baidu.com/
非结构化数据的保存方式
像压缩文件zip、图片文件等都可以使用非结构化数据的保存方式
with open('xxx.jpg','wb') as f: f.write(res.content)
示例：保存赵丽颖图片到本地
import requests url = 'http://dingyue.nosdn.127.net/lL1JH2YdpAWrzEhfp8BrJ8lTHa1602AEX9E7qpTpH5NzW1535203788506compressflag.jpg' headers = {'User-Agent': 'Mozilla/5.0'} html = requests.get(url, headers=headers).content # 把图片保存到本地 with open('赵丽颖.jpg', 'wb') as f: f.write(html)
百度贴吧图片抓取
目标：抓取指定贴吧所有图片
思路
- 获取贴吧主页URL，下一页，找到不同页的URL规律
- 获取1页中所有帖子URL地址: [帖子链接1,帖子链接2,…]
- 对每个帖子链接发请求，获取图片URL
- 向图片的URL发请求，以wb方式写入本地文件
贴吧URL规律：http://tieba.baidu.com/f?kw=??&pn=50
xpath表达式
1、帖子链接xpath，这里为什么属性选择class，因为相同的元素他们要相同的样式
//div[@class="t_con cleafix"]/div/div/div/a/@href
2、图片链接xpath
//div[@class="d_post_content j_d_post_content clearfix"]/img[@class="BDE_Image"]/@src
3、视频链接xpath
//div[@class="video_src_wrapper"]/embed/@data-video
# 注意: 此处视频链接前端对响应内容做了处理，需要查看网页源代码来查看，复制HTML代码在线格式化
百度贴吧视频抓取反爬机制（对响应内容做处理）
网页源代码是：
<div class=”video_src_wrapper”>
<embed data-video=”http://tb-video.bdstatic.com/tieba-smallvideo-transcode-cae/2754153_8fcd225842344de9901c1489e49defbe_0_cae.mp4″
F12调试定位到的代码是：
<div class="video_src_wrapper"> <div class="video_src_wrap_main"> <video src="http://tb-video.bdstatic.com/tie-cae/f2358e8_0_cae.mp4" "></video> </div> </div>
如果通过F12定位的位置，写xpath，会爬取不到，因为我们requsets爬取的是网页代码，最后还是要以网页源代码为主。
import requests from lxml import etree import random import time from urllib import parse class BaiduImageSpider(object): def __init__(self): self.url = 'http://tieba.baidu.com/f?kw={}&pn={}' self.ua_list = [ 'Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/535.1 (KHTML, like Gecko) Chrome/14.0.835.163 Safari/535.1', 'Mozilla/5.0 (Windows NT 6.1; WOW64; rv:6.0) Gecko/20100101 Firefox/6.0', 'Mozilla/4.0 (compatible; MSIE 8.0; Windows NT 6.1; WOW64; Trident/4.0; SLCC2; .NET CLR 2.0.50727; .NET CLR 3.5.30729; .NET CLR 3.0.30729; Media Center PC 6.0; .NET4.0C; InfoPath.3)', ] # 获取html网页代码 def get_html(self, url): headers = {'User-Agent': random.choice(self.ua_list)} html = requests.get(url=url, headers=headers).content.decode('utf-8', 'ignore') return html # 解析html def xpath_func(self, html, xpath_bds): parse_html = etree.HTML(html) r_list = parse_html.xpath(xpath_bds) return r_list # 图片抓取 def parse_html(self, one_url): html = self.get_html(one_url) xpath_bds = '//div[@class="t_con cleafix"]/div/div/div/a/@href' r_list = self.xpath_func(html, xpath_bds) # 提取帖子链接:xpath_list ['/p/32323','',''] for r in r_list: t_url = 'http://tieba.baidu.com' + r # 拼接帖子的URL地址 self.get_image(t_url) # 把帖子中所有图片保存到本地 time.sleep(random.uniform(0, 2)) # 爬完1个帖子中所有图片,休眠0-2秒钟 # 给定1个帖子URL,把帖子中所有图片保存到本地 def get_image(self, t_url): html = self.get_html(t_url) # 使用xpath表达式的或| : 图片链接 + 视频链接 xpath_bds = '//div[@class="d_post_content j_d_post_content clearfix"]/img[@class="BDE_Image"]/@src | //div[@class="video_src_wrapper"]/embed/@data-video' img_list = self.xpath_func(html, xpath_bds) # ['http://xxx.jpg',''] print(img_list) for img in img_list: html_bytes = requests.get(url=img, headers={'User-Agent': random.choice(self.ua_list)}).content self.save_img(html_bytes, img) # 保存图片函数 def save_img(self, html_bytes, img): filename = img[-10:] with open(filename, 'wb') as f: f.write(html_bytes) print('%s下载成功' % filename) # 主函数 def main(self): name = input('请输入贴吧名:') begin = int(input('请输入起始页:')) end = int(input('请输入终止页:')) # 对贴吧名进行编码 kw = parse.quote(name) for page in range(begin, end + 1): pn = (page - 1) * 50 url = self.url.format(kw, pn) # 调用主线函数 self.parse_html(url) if __name__ == '__main__': spider = BaiduImageSpider() spider.main()
查询参数-params
res = requests.get(url,params=params,headers=headers)
url为基准的url地址，不包含查询参数，该方法会自动对params字典编码，然后和url拼接
参数类型：字典,字典中键值对作为查询参数
import requests baseurl = 'http://tieba.baidu.com/f?' params = { 'kw': '赵丽颖吧', 'pn': '50'} headers = {'User-Agent': 'Mozilla/4.0 (compatible; MSIE 8.0; Windows NT 6.1; WOW64; Trident/4.0; SLCC2 ; .NET CLR 2.0.50727; .NET CLR 3.5.30729; .NET CLR 3.0.30729; Media Center PC 6.0; .NET4.0C; InfoPath.3)'} # 自动对params进行编码,然后自动和url进行拼接,去发请求 res = requests.get(baseurl, headers=headers, params=params) res.encoding = 'utf-8' print(res.text)
Web客户端验证参数-auth
res = requests.get(url, headers=headers, auth=(‘username’,’password’))
针对于需要web客户端用户名密码认证的网站，auth = (‘username’,’password’)
达内课程笔记
import requests from lxml import etree import random import os class CodeSpider(object): def __init__(self): self.url = 'http://code.tarena.com.cn/AIDCode/aid1904/14-redis/' self.auth = ('tarenacode', 'code_2013') self.ua_list = [ 'Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/535.1 (KHTML, like Gecko) Chrome/14.0.835.163 Safari/535.1', 'Mozilla/5.0 (Windows NT 6.1; WOW64; rv:6.0) Gecko/20100101 Firefox/6.0', 'Mozilla/4.0 (compatible; MSIE 8.0; Windows NT 6.1; WOW64; Trident/4.0; SLCC2; .NET CLR 2.0.50727; . NET CLR 3.5.30729; .NET CLR 3.0.30729; Media Center PC 6.0; .NET4.0C; InfoPath.3)', ] def parse_html(self): # 获取响应内容 html = requests.get(url=self.url, headers={'User-Agent': random.choice(self.ua_list)}, auth=self.auth) html = html.content.decode('utf-8', 'ignore') parse_html = etree.HTML(html) # 解析 r_list = parse_html.xpath('//a/@href') # # r_list : ['../','day01','day02','redis_day01.zip'] for r in r_list: if r.endswith('.zip') or r.endswith('.rar'): self.save_files(r) def save_files(self, r): directory = '/home/tarena/AID/redis/' if not os.path.exists(directory): os.makedirs(directory) # 拼接地址,把zip文件保存到指定目录 url = self.url + r # filename: /home/tarena/AID/redis/xxx.zip filename = directory + r html = requests.get(url=url, headers={'User-Agent': random.choice(self.ua_list)}, auth=self.auth).content with open(filename, 'wb') as f: f.write(html) print('%s下载成功' % r) if __name__ == '__main__': spider = CodeSpider() spider.parse_html()
SSL证书认证参数-verify
response = requests.get(url=url,params=params,headers=headers,verify=False)
SSL证书认证参适用于没有经过 证书认证机构认证的https类型网站，一般这种网站会抛出 SSLError 异常则考虑使用此参数
verify：True(默认)检查证书认证；False（常用）忽略证书认证
代理参数-proxies
定义：代替你原来的IP地址去对接网络的IP地址。隐藏自身真实IP，避免被封。
普通代理
获取代理IP网站：西刺代理、快代理、全网代理、代理精灵、… …
语法结构
proxies = {'协议':'协议://IP:端口号'} # http和https是相同的 proxies = { 'http':'http://59.172.27.6:38380', 'https':'https://59.172.27.6:38380' }
使用免费普通代理IP访问测试网站: http://httpbin.org/get
import requests url = 'http://httpbin.org/get' headers = {'User-Agent': 'Mozilla/5.0'} # 定义代理,在代理IP网站中查找免费代理IP proxies = { 'http': 'http://309435365:[email protected]:16818', 'https': 'https://309435365:[email protected]:16818'} html = requests.get(url, proxies=proxies, headers=headers, timeout=5).text print(html)
IP池
从西刺代理上面爬取IP，迭代测试能否使用，建立一个自己的代理IP池，随时更新用来抓取网站数据
import requests from lxml import etree import time import random from fake_useragent import UserAgent class GetProxyIP(object): def __init__(self): self.url = 'https://www.xicidaili.com/nn/' self.proxies = { 'http': 'http://163.204.247.219:9999', 'https': 'http://163.204.247.219:9999'} # 随机生成User-Agent def get_random_ua(self): ua = UserAgent() # 创建User-Agent对象 useragent = ua.random return useragent # 从西刺代理网站上获取随机的代理IP def get_ip_file(self, url): headers = {'User-Agent': self.get_random_ua()} # 访问西刺代理网站国内高匿代理，找到所有的tr节点对象 html = requests.get(url=url, proxies=self.proxies, headers=headers, timeout=5).content.decode('utf-8', 'ignore') parse_html = etree.HTML(html) # 基准xpath，匹配每个代理IP的节点对象列表 tr_list = parse_html.xpath('//tr') for tr in tr_list[1:]: ip = tr.xpath('./td[2]/text()')[0] port = tr.xpath('./td[3]/text()')[0] # 测试ip:port是否可用 self.test_proxy_ip(ip, port) # 测试抓取的代理IP是否可用 def test_proxy_ip(self, ip, port): proxies = { 'http': 'http://{}:{}'.format(ip, port), 'https': 'https://{}:{}'.format(ip, port), } test_url = 'http://www.baidu.com/' try: res = requests.get(url=test_url, proxies=proxies, timeout=8) if res.status_code == 200: print(ip, ":", port, 'Success') with open('proxies.txt', 'a') as f: f.write(ip + ':' + port + 'n') except Exception as e: print(ip, port, 'Failed') # 主函数 def main(self): for i in range(1, 1001): url = self.url.format(i) self.get_ip_file(url) time.sleep(random.randint(5, 10)) if __name__ == '__main__': spider = GetProxyIP() spider.main()
从IP池中取IP
从文件中随机获取代理IP写爬虫
import random import requests class BaiduSpider(object): def __init__(self): self.url = 'http://www.baidu.com/' self.headers = {'User-Agent': 'Mozilla/5.0'} self.blag = 1 def get_proxies(self): with open('proxies.txt', 'r') as f: result = f.readlines() # 读取所有行并返回列表 proxy_ip = random.choice(result)[:-1] # 获取了所有代理IP L = proxy_ip.split(':') proxy_ip = { 'http': 'http://{}:{}'.format(L[0], L[1]), 'https': 'https://{}:{}'.format(L[0], L[1]) } return proxy_ip def get_html(self): proxies = self.get_proxies() if self.blag <= 3: try: html = requests.get(url=self.url, proxies=proxies, headers=self.headers, timeout=5).text print(html) except Exception as e: print('Retry') self.blag += 1 self.get_html() if __name__ == '__main__': spider = BaiduSpider() spider.get_html()
收费代理API
写一个获取收费开放API代理的接口
# 获取开放代理的接口 import requests from fake_useragent import UserAgent ua = UserAgent() # 创建User-Agent对象 useragent = ua.random headers = {'User-Agent': useragent} def ip_test(ip): url = 'http://www.baidu.com/' ip_port = ip.split(':') proxies = { 'http': 'http://{}:{}'.format(ip_port[0], ip_port[1]), 'https': 'https://{}:{}'.format(ip_port[0], ip_port[1]), } res = requests.get(url=url, headers=headers, proxies=proxies, timeout=5) if res.status_code == 200: return True else: return False # 提取代理IP def get_ip_list(): # 快代理：https://www.kuaidaili.com/doc/product/dps/ api_url = 'http://dev.kdlapi.com/api/getproxy/?orderid=946562662041898&num=100&protocol=1&method=2&an_an=1&an_ha=1&sep=2' html = requests.get(api_url).content.decode('utf-8', 'ignore') ip_port_list = html.split('n') for ip in ip_port_list: with open('proxy_ip.txt', 'a') as f: if ip_test(ip): f.write(ip + 'n') if __name__ == '__main__': get_ip_list()
私密代理
1、语法结构
proxies = { '协议':'协议://用户名:密码@IP:端口号' } proxies = { 'http':'http://用户名:密码@IP:端口号', 'https':'https://用户名:密码@IP:端口号' } proxies = { 'http': 'http://309435365:[email protected]:16816', 'https':'https://309435365:[email protected]:16816', }
用户名和密码会在给你API_URL的时候给你。不是你的账号和账号密码。
# 获取开放代理的接口 import requests from fake_useragent import UserAgent ua = UserAgent() # 创建User-Agent对象 useragent = ua.random headers = {'User-Agent': useragent} def ip_test(ip): url = 'https://blog.csdn.net/qq_34218078/article/details/90901602/' ip_port = ip.split(':') proxies = { 'http': 'http://1786088386:b95djiha@{}:{}'.format(ip_port[0], ip_port[1]), 'https': 'http://1786088386:b95djiha@{}:{}'.format(ip_port[0], ip_port[1]), } res = requests.get(url=url, headers=headers, proxies=proxies, timeout=5) if res.status_code == 200: print("OK") return True else: print(res.status_code) print("错误") return False # 提取代理IP def get_ip_list(): # 快代理：https://www.kuaidaili.com/doc/product/dps/ api_url = 'http://dps.kdlapi.com/api/getdps/?orderid=986603271748760&num=1000&signature=z4a5b2rpt062iejd6h7wvox16si0f7ct&pt=1&sep=2' html = requests.get(api_url).content.decode('utf-8', 'ignore') ip_port_list = html.split('n') for ip in ip_port_list: with open('proxy_ip.txt', 'a') as f: if ip_test(ip): f.write(ip + 'n') if __name__ == '__main__': get_ip_list()
