python爬虫之requests模块2

python网络爬虫之requests模块

• session处理cookie
• proxies参数设置请求代理ip
• 基于线程池的数据爬取

一 获取验证码

步骤：

​ 1 注册云大码 http://www.yundama.com/about.html

​ 2登陆 开发者登陆 和用户者登陆

3 在开发者登陆成功以后，建立新软件

4点击开发者中心

5 点击进入Pythonhttp下载

6 选择所需的版本下载便可

获取验证码

import http.client, mimetypes, urllib, json, time, requests

######################################################################

class YDMHttp:

    apiurl = 'http://api.yundama.com/api.php'
    username = ''
    password = ''
    appid = ''
    appkey = ''

    def __init__(self, username, password, appid, appkey):
        self.username = username  
        self.password = password
        self.appid = str(appid)
        self.appkey = appkey

    def request(self, fields, files=[]):
        response = self.post_url(self.apiurl, fields, files)
        response = json.loads(response)
        return response
    
    def balance(self):
        data = {'method': 'balance', 'username': self.username, 'password': self.password, 'appid': self.appid, 'appkey': self.appkey}
        response = self.request(data)
        if (response):
            if (response['ret'] and response['ret'] < 0):
                return response['ret']
            else:
                return response['balance']
        else:
            return -9001
    
    def login(self):
        data = {'method': 'login', 'username': self.username, 'password': self.password, 'appid': self.appid, 'appkey': self.appkey}
        response = self.request(data)
        if (response):
            if (response['ret'] and response['ret'] < 0):
                return response['ret']
            else:
                return response['uid']
        else:
            return -9001

    def upload(self, filename, codetype, timeout):
        data = {'method': 'upload', 'username': self.username, 'password': self.password, 'appid': self.appid, 'appkey': self.appkey, 'codetype': str(codetype), 'timeout': str(timeout)}
        file = {'file': filename}
        response = self.request(data, file)
        if (response):
            if (response['ret'] and response['ret'] < 0):
                return response['ret']
            else:
                return response['cid']
        else:
            return -9001

    def result(self, cid):
        data = {'method': 'result', 'username': self.username, 'password': self.password, 'appid': self.appid, 'appkey': self.appkey, 'cid': str(cid)}
        response = self.request(data)
        return response and response['text'] or ''

    def decode(self, filename, codetype, timeout):
        cid = self.upload(filename, codetype, timeout)
        if (cid > 0):
            for i in range(0, timeout):
                result = self.result(cid)
                if (result != ''):
                    return cid, result
                else:
                    time.sleep(1)
            return -3003, ''
        else:
            return cid, ''

    def report(self, cid):
        data = {'method': 'report', 'username': self.username, 'password': self.password, 'appid': self.appid, 'appkey': self.appkey, 'cid': str(cid), 'flag': '0'}
        response = self.request(data)
        if (response):
            return response['ret']
        else:
            return -9001

    def post_url(self, url, fields, files=[]):
        for key in files:
            files[key] = open(files[key], 'rb');
        res = requests.post(url, files=files, data=fields)
        return res.text

######################################################################

# 云打码中的用户名（普通用户）
username    = 'molihua'

# 云打码中的密码
password    = 'MLH19960208'                            

# 软件ＩＤ，开发者分红必要参数。登陆开发者后台【个人软件】得到！
appid       = 7025                                  

# 软件密钥，开发者分红必要参数。登陆开发者后台【个人软件】得到！
appkey      = '2d96c723a682c882faa73257e98440d7 '    

# 图片文件  
filename    = 'getimage.jpg'                        

# 验证码类型，# 例：1004表示4位字母数字，不一样类型收费不一样。请准确填写，不然影响识别率。在此查询全部类型 http://www.yundama.com/price.html
codetype    = 1004

# 超时时间，秒 自定义
timeout     = 10                                   

# 检查
if (username == 'username'):
    print('请设置好相关参数再测试')
else:
    # 初始化
    yundama = YDMHttp(username, password, appid, appkey)

    # 登录云打码
    uid = yundama.login();
    print('uid: %s' % uid)

    # 查询余额
    balance = yundama.balance();
    print('balance: %s' % balance)

    # 开始识别，图片路径，验证码类型ID，超时时间（秒），识别结果
    cid, result = yundama.decode(filename, codetype, timeout);
    print('cid: %s, result: %s' % (cid, result))

需求 经过登陆人人网来获取主页面

import requests
import urllib
from lxml import etree

#获取session对象
session=requests.Session()
url='http://www.renren.com'
headers={
    'User-Agent':'Mozilla/5.0 (Windows NT 10.0; WOW64; rv:65.0) Gecko/20100101 Firefox/65.0'
}
renren_text = requests.get(url=url,headers=headers).text
tree = etree.HTML(renren_text)
code_img_url = tree.xpath('//*[@id="verifyPic_login"]/@src')[0]
urllib.requests.urlretrieve(url=code_img_url,filename='code.jpg')

#识别验证码图片中的数据值

code_data = getCodeDate('15204558261','MLH19960208','./code.jpg',2004)
print(code_data)

login_url = 'http://www.renren.com/ajaxLogin/login?1=1&uniqueTimestamp=2019142013687'

##经过抓包工具来获取
data ={
    'email':'15204558261'
    'icode': code_data
    'origURL':'http://www.renren.com/home'
    'domain':'renren.com'
    'key_id':'1'
    'captcha_type':'web_login'
    'password':'7bf638cc5b01b15b9416bf17fb98a1eda46da861c139b563a4c670fb21884336'
    'rkey':'cf9180c5afba43cb1f089b953e67b567'
    'f':'http%3A%2F%2Fwww.renren.com%2F296856777%2Fprofile'
}
#该次请求产生的cookie会被自动存储到session对象中

session.post(url=login_url,data=data,headers=headers)
url='http://www.renren.com/296856777/profile'
page_text = session.get(url=url,headers=headers).text

with open('renren.html','w',encoding='utf-8') as fp:
    fp.write(page_text)

基于multiprocessing.dummy线程池的数据爬取

import requests
import random
from lxml import etree
import re
from fake_useragent import UserAgent
#安装fake-useragent库:pip install fake-useragent
#导入线程池模块
from multiprocessing.dummy import Pool
#实例化线程池对象
pool = Pool()
url = 'http://www.pearvideo.com/category_1'
#随机产生UA
ua = UserAgent().random
headers = {
    'User-Agent':ua
}
#获取首页页面数据
page_text = requests.get(url=url,headers=headers).text
#对获取的首页页面数据中的相关视频详情连接进行解析
tree = etree.HTML(page_text)
li_list = tree.xpath('//div[@id="listvideoList"]/ul/li')

detail_urls = []#存储二级页面的url
for li in li_list:
    detail_url = 'http://www.pearvideo.com/'+li.xpath('./div/a/@href')[0]
    title = li.xpath('.//div[@class="vervideo-title"]/text()')[0]
    detail_urls.append(detail_url)
    
vedio_urls = []#存储视频的url
for url in detail_urls:
    page_text = requests.get(url=url,headers=headers).text
    vedio_url = re.findall('srcUrl="(.*?)"',page_text,re.S)[0]
    vedio_urls.append(vedio_url) 
#使用线程池进行视频数据下载    
func_request = lambda link:requests.get(url=link,headers=headers).content
video_data_list = pool.map(func_request,vedio_urls)
#使用线程池进行视频数据保存
func_saveData = lambda data:save(data)
pool.map(func_saveData,video_data_list)
def save(data):
    fileName = str(random.randint(1,10000))+'.mp4'
    with open(fileName,'wb') as fp:
        fp.write(data)
        print(fileName+'已存储')
        
pool.close()
pool.join()

requests模块的代理

什么是代理？？？

​ 代理就是第三方代替本体来处理相关的事务。列如：中介，微商，代购等

那么问题来了，爬虫为何要用到代理呢？

​ 这是由于有一些网站它会采起相关的反爬措施。列如一些网站会经过检测某一段时间某个IP访问的次数，若是访问太过于频繁，那么它就会知道可能不是正常的用户，会禁止掉这个IP的访问。因此咱们可使用代理IP来爬取咱们须要的数据，就算是某一个ＩＰ一段时间被禁止掉，也能够换另外一个代理

ＩＰ去爬取数据。是否是以为很是的神奇呢

代理的分类：

正向代理：代理客户端获取数据

反向代理：代理服务端提供数据

免费代理IP的网站：

http://www.goubanjia.com/

快代理

import requests
import random
if __name__ == "__main__":
    #不一样浏览器的UA
    header_list = [
        # 遨游
        {"user-agent": "Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 5.1; Maxthon 2.0)"},
        # 火狐
        {"user-agent": "Mozilla/5.0 (Windows NT 6.1; rv:2.0.1) Gecko/20100101 Firefox/4.0.1"},
        # 谷歌
        {
            "user-agent": "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_7_0) AppleWebKit/535.11 (KHTML, like Gecko) Chrome/17.0.963.56 Safari/535.11"}
    ]
    #不一样的代理IP
    proxy_list = [
        {"http": "112.115.57.20:3128"},
        {'http': '121.41.171.223:3128'}
    ]
    #随机获取UA和代理IP
    header = random.choice(header_list)
    proxy = random.choice(proxy_list)

    url = 'http://www.baidu.com/s?ie=UTF-8&wd=ip'
    #参数3：设置代理
    response = requests.get(url=url,headers=header,proxies=proxy)
    response.encoding = 'utf-8'
    
    with open('daili.html', 'wb') as fp:
        fp.write(response.content)
    #切换成原来的IP
    requests.get(url, proxies={"http": ""})