爬虫 -requests
requests模块
- 1.什么是requests模块
- python原生一个基于网络请求的模块，模拟浏览器发起请求。
- 2.为什么要使用requests模块
- 1.自动处理url编码
- 2.自动处理post请求的参数
- 3.简化cookie的代理的操作：
cookie操作：
- 创建一个cookiejar对象
- 创建一个handler对象
- 创建一个operner
代理操作：
- 创建handler对象，代理ip和端口封装到该对象
- 创建openner对象
- 3.requests如何被使用
- 安装：pip install requests
- 使用流程：
- 1.指定url
- 2.使用requests模块发起请求
- 3.获取响应数据
- 4.进行持久化存储
- 4.通过5个基于requests模块的爬虫项目对该模块进行系统学习和巩固
- get请求
- post请求
- ajax的get
- ajax的post
- 综合
- cookie
- 代理
1 基于requests模块发起get请求
- 需求：爬取搜狗首页的页面数据
import requests
#指定url
url = 'https://www.sogou.com/'
#发起get请求:get方法会返回请求成功的相应对象
response = requests.get(url=url)
#获取响应中的数据值:text可以获取响应对象中字符串形式的页面数据
page_data = response.text
print(page_data)
#持久化操作
with open('./sougou.html','w',encoding='utf-8') as fp:
fp.write(page_data)
response对象中其他重要的属性
#response对象中其他重要的属性
import requests
#指定url
url = 'https://www.sogou.com/'
#发起get请求:get方法会返回请求成功的相应对象
response = requests.get(url=url)
#content获取的是response对象中二进制（byte）类型的页面数据
# print(response.content)
#返回一个响应状态码
# print(response.status_code)
#返回响应头信息
# print(response.headers)
#获取请求的url
# print(response.url)
https://www.sogou.com/
- requests模块如何处理携带参数的get请求
方式1：- 需求：指定一个词条，获取搜狗搜索结果所对应的页面数据
import requests
url = 'https://www.sogou.com/web?query=周杰伦&ie=utf-8'
response = requests.get(url=url)
page_text = response.text
with open('./zhou.html','w',encoding='utf-8') as fp:
fp.write(page_text)
# 自定义请求头信息
import requests
url = 'https://www.sogou.com/web'
#将参数封装到字典中
params = {
'query':'周杰伦',
'ie':'utf-8'
}
#自定义请求头信息
headers = {
'User-Agent': 'Mozilla/5.0 (Macintosh; Intel Mac OS X 10_12_0) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/69.0.3497.100 Safari/537.36',
}
response = requests.get(url=url,params=params,headers=headers)
response.status_code
200
2 基于requests模块发起的post请求
- 需求：登录豆瓣网，获取登录成功后的页面数据
import requests
#1.指定post请求的url
url = 'https://accounts.douban.com/login'
#封装post请求的参数
data = {
"source": "movie",
"redir": "https://movie.douban.com/",
"form_email": "15027900535",
"form_password": "bobo@15027900535",
"login": "登录",
}
#自定义请求头信息
headers = {
'User-Agent': 'Mozilla/5.0 (Macintosh; Intel Mac OS X 10_12_0) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/69.0.3497.100 Safari/537.36',
}
#2.发起post请求
response = requests.post(url=url,data=data,headers=headers)
#3.获取响应对象中的页面数据
page_text = response.text
#4.持久化操作
with open('./douban.html','w',encoding='utf-8') as fp:
fp.write(page_text)
基于ajax的get请求
-需求：抓取豆瓣电影上电影详情的数据
import requests
url = 'https://movie.douban.com/j/chart/top_list?'
#封装ajax的get请求中携带的参数
params = {
'type':'5',
'interval_id':'100:90',
'action':'',
'start':'200',
'limit':'20'
}
#自定义请求头信息
headers = {
'User-Agent': 'Mozilla/5.0 (Macintosh; Intel Mac OS X 10_12_0) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/69.0.3497.100 Safari/537.36',
}
response = requests.get(url=url,params=params,headers=headers)
# print(response.text)
基于ajax的post请求
- 需求：爬去肯德基城市餐厅位置数据
import requests
#1指定url
post_url = 'http://www.kfc.com.cn/kfccda/ashx/GetStoreList.ashx?op=keyword'
#处理post请求的参数
data = {
"cname": "",
"pid": "",
"keyword": "上海",
"pageIndex": "1",
"pageSize": "10",
}
#自定义请求头信息
headers = {
'User-Agent': 'Mozilla/5.0 (Macintosh; Intel Mac OS X 10_12_0) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/69.0.3497.100 Safari/537.36',
}
#2发起基于ajax的post请求
response = requests.post(url=post_url,headers=headers,data=data)
response.text
'{"Table":[{"rowcount":28}],"Table1":[{"rownum":1,"storeName":"开发区上海路","addressDetail":"开发区上海路80号乐天玛特超一楼","pro":"Wi-Fi,礼品卡,生日餐会","provinceName":"江苏省","cityName":"南通市"},{"rownum":2,"storeName":"太仓新区东亭路","addressDetail":"太仓市娄江路与县府街交叉口西南侧（太仓新区上海路北、东亭路东地块）万达广场","pro":"Wi-Fi,店内参观,礼品卡,生日餐会","provinceName":"江苏省","cityName":"苏州市"},{"rownum":3,"storeName":"动力南广场（汇金奥特莱斯B1层）","addressDetail":"石龙路750-3号上海南站地下商场南馆","pro":"精选店,礼品卡","provinceName":"上海市","cityName":"上海市"},{"rownum":4,"storeName":"谷阳","addressDetail":"松汇中路568号上海鹿都商业广场","pro":"Wi-Fi,店内参观,礼品卡,生日餐会,溯源","provinceName":"上海市","cityName":"上海市"},{"rownum":5,"storeName":"南广场","addressDetail":"秣陵路303号上海火车站西南出口一侧","pro":"Wi-Fi,礼品卡","provinceName":"上海市","cityName":"上海市"},{"rownum":6,"storeName":"北广场","addressDetail":"秣陵路303号上海站北广场北立面1F大厅入口西侧位置","pro":"Wi-Fi","provinceName":"上海市","cityName":"上海市"},{"rownum":7,"storeName":"南站精选（火车站站内）","addressDetail":"沪闵路9001号上海南站候车大厅","pro":"精选店,礼品卡","provinceName":"上海市","cityName":"上海市"},{"rownum":8,"storeName":"上海滩","addressDetail":"佘山林湖路888号-1上海滩区5号","pro":"精选店,礼品卡","provinceName":"上海市","cityName":"上海市"},{"rownum":9,"storeName":"动力南精选（3号线2号出口）","addressDetail":"沪闵路9001号上海南站（1F三角地A-1）一层","pro":"精选店,礼品卡","provinceName":"上海市","cityName":"上海市"},{"rownum":10,"storeName":"上海南路","addressDetail":"上海南路3号699生活空间3号楼","pro":"Wi-Fi,店内参观,礼品卡,生日餐会","provinceName":"江西省","cityName":"南昌市"}]}'
3 综合项目实战
- 需求：爬取搜狗知乎某一个词条对应一定范围页码表示的页面数据
import os
#前三页页面数据（1，2，3）
import requests
import os
#创建一个文件夹
if not os.path.exists('./pages'):
os.mkdir('./pages')
word = input('enter a word:')
#动态指定页码的范围
start_pageNum = int(input('enter a start pageNum:'))
end_pageNum = int(input('enter a end pageNum:'))
#自定义请求头信息
headers = {
'User-Agent': 'Mozilla/5.0 (Macintosh; Intel Mac OS X 10_12_0) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/69.0.3497.100 Safari/537.36',
}
#1.指定url:设计成一个具有通用的url
url = 'https://zhihu.sogou.com/zhihu'
for page in range(start_pageNum,end_pageNum+1):
param = {
'query':word,
'page':page,
'ie':'utf-8'
}
response = requests.get(url=url,params=param,headers=headers)
#获取响应中的页面数据（指定页码（page））
page_text = response.text
#进行持久化存储
fileName = word+str(page)+'.html'
filePath = 'pages/'+fileName
with open(filePath,'w',encoding='utf-8') as fp:
fp.write(page_text)
print('第%d页数据写入成功'%page)
enter a word:python
enter a start pageNum:3
enter a end pageNum:5
第3页数据写入成功
第4页数据写入成功
第5页数据写入成功
4 cookie：
- cookie：
基于用户的用户数据
- 需求：爬取张三用户的豆瓣网的个人主页页面数据
- cookie作用：服务器端使用cookie来记录客户端的状态信息。
实现流程：
1.执行登录操作（获取cookie）
2.在发起个人主页请求时，需要将cookie携带到该请求中
注意：session对象：发送请求（会将cookie对象进行自动存储）
- 代理：
#问题：没有获取个人主页的页面数据
#原因：爬虫程序没有严格遵从浏览器的请求流程
import requests
#1.指定url
url = 'https://www.douban.com/people/185687620/'
headers={
'User-Agent': 'Mozilla/5.0 (Macintosh; Intel Mac OS X 10_12_0) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/69.0.3497.100 Safari/537.36',
}
#2.发起请求
response = requests.get(url=url,headers=headers)
#3.获取页面数据
page_text = response.text
#4.持久化存储
with open('./douban.html','w',encoding='utf-8') as fp:
fp.write(page_text)
import requests
session = requests.session()
#1.发起登录请求：将cookie获取，切存储到session对象中
login_url = 'https://accounts.douban.com/login'
data = {
"source": "None",
"redir": "https://www.douban.com/people/185687620/",
"form_email": "15027900535",
"form_password": "bobo@15027900535",
"login": "登录",
}
headers={
'User-Agent': 'Mozilla/5.0 (Macintosh; Intel Mac OS X 10_12_0) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/69.0.3497.100 Safari/537.36',
}
#使用session发起post请求
login_response = session.post(url=login_url,data=data,headers=headers)
#2.对个人主页发起请求（session（cookie）），获取响应页面数据
url = 'https://www.douban.com/people/185687620/'
response = session.get(url=url,headers=headers)
page_text = response.text
with open('./douban110.html','w',encoding='utf-8') as fp:
fp.write(page_text)
5 代理操作：
- 1.代理：第三方代理本体执行相关的事物。生活：代购，微商，中介
- 2.为什么要使用代理？
- 反爬操作。
- 反反爬手段
- 3.分类：
- 正向代理：代替客户端获取数据
- 反向代理：代理服务器端提供数据
- 4.免费代理ip的网站提供商：
- www.goubanjia.com
- 快代理
- 西祠代理
- 5.代码：
import requests
url = 'http://www.baidu.com/s?ie=utf-8&wd=ip'
headers={
'User-Agent': 'Mozilla/5.0 (Macintosh; Intel Mac OS X 10_12_0) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/69.0.3497.100 Safari/537.36',
}
#将代理ip封装到字典
proxy = {
'http':'77.73.69.120:3128'
}
#更换网路IP
response = requests.get(url=url,proxies=proxy,headers=headers)
with open('./daili.html','w',encoding='utf-8') as fp:
fp.write(response.text)
作者：华王
博客：https://www.cnblogs.com/huahuawang/
