## 3 requests模块使用
```python
1 安装：pip3 install requests
2 图片防盗链：referer
3 代码
import requests
# 1 发送get请求
# res是python的对象，对象里，响应头，响应体。。。。
# header = {
# 'user-agent': 'Mozilla/5.0 (Windows NT 10.0; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/84.0.4147.105 Safari/537.36',
# 'referer': 'https://www.mzitu.com/225078/2'
# }
# # res = requests.get('https://www.mzitu.com/', headers=header)
# # print(res.text)
# res1 = requests.get('https://i3.mmzztt.com/2020/03/14a02.jpg', headers=header)
# print(res1.text)
# # print(res1.content) # 二进制内容
#
# with open('a.jpg', 'wb')as f:
# for line in res1.iter_content():
# f.write(line)
# 2 请求地址中携带数据(两种方式，推荐第二种)
# from urllib.parse import urlencode,unquote # url的编码和解码
# print(unquote('%E7%BE%8E%E5%A5%B3'))
# %E7%BE%8E%E5%A5%B3
# header = {
# 'user-agent': 'Mozilla/5.0 (Windows NT 10.0; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/84.0.4147.105 Safari/537.36',
# }
# # res=requests.get('https://www.baidu.com/s?wd=美女',headers=header)
# res=requests.get('https://www.baidu.com/s',headers=header,params={'wd':'美女'})
# print(res.url)
# print(res.text)
# 3 请求带cookie(两种方式)
# 方式一，在header中放
# header = {
# 'user-agent': 'Mozilla/5.0 (Windows NT 10.0; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/84.0.4147.105 Safari/537.36',
# 'cookie':'key=asdfasdfasdfsdfsaasdf;key2=asdfasdf;key3=asdfasdf'
# }
# res=requests.get('http://127.0.0.1:8000/index/',headers=header)
# 方式二：
# header = {
# 'user-agent': 'Mozilla/5.0 (Windows NT 10.0; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/84.0.4147.105 Safari/537.36',
# }
# # cookies是一个字典或者CookieJar对象
# res=requests.get('http://127.0.0.1:8000/index/',headers=header,cookies={'key':'asdfasdf'})
# print(res.text)
# 问：你的网站从哪取出cookie来
# 4 发送post请求，携带数据（urlencoded和json）
# res=requests.post('http://127.0.0.1:8000/index/',data={'name':'lqz'})
# print(res.text)
# res=requests.post('http://127.0.0.1:8000/index/',json={'age':1,},)
# print(res.text)
# 5 自动携带cookie
# session=requests.session()
# res=session.post('http://127.0.0.1:8000/index/') # 假设这个请求登录了
# res1=session.get('http://127.0.0.1:8000/order/') # 现在不需要手动带cookie，session会帮咱处理
# 6 response对象
# respone=requests.post('http://127.0.0.1:8000/index/',data={'name':'lqz'})
# # print(respone.text) # 响应的文本
# print(respone.content) # 响应体的二进制
#
#
# print(respone.status_code) # 响应状态码
# print(respone.headers) # 响应头
# print(respone.cookies) # cookie
# print(respone.cookies.get_dict()) # 把cookie转成字典
# print(respone.cookies.items()) # key和value
#
# print(respone.url) # 请求的url
# print(respone.history) #[]放重定向之前的地址
#
# print(respone.encoding) # 响应的编码方式
# respone.iter_content() # 图片，视频，大文件，一点一点循环取出来
# for line in respone.iter_content():
# f.write(line)
# 7 编码问题
# res=requests.get('http://www.autohome.com/news')
# # 一旦打印出来出现乱码问题
# # 方式一
# # res.encoding='gb2312'
# # 方式二
# res.encoding=res.apparent_encoding
# print(res.text)
# 8 解析json
# import json
# respone=requests.post('http://127.0.0.1:8000/index/',data={'name':'lqz'})
# # print(type(respone.text)) # 响应的文本
# # print(json.loads(respone.text))
# print(respone.json()) # 相当于上面那句话
# print(type(respone.json())) # 相当于上面那句话
# 9 高级用法之ssl（了解）
# import requests
# respone=requests.get('https://www.12306.cn') #不验证证书,报警告,返回200
# print(respone.status_code)
# 使用证书，需要手动携带
# import requests
# respone=requests.get('https://www.12306.cn',
# cert=('/path/server.crt',
# '/path/key'))
# print(respone.status_code)
# 10 高级用法：使用代理
# respone=requests.get('http://127.0.0.1:8000/index/',proxies={'http':'代理的地址和端口号',})
# 代理，免费代理，收费代理花钱买
# 代理池：列表放了一堆代理ip，每次随机取一个，再发请求就不会封ip了
# 高匿和透明代理？如果使用高匿代理，后端无论如何拿不到你的ip，使用透明，后端能够拿到你的ip
# 后端如何拿到透明代理的ip， 后端：X-Forwarded-For
# respone=requests.get('https://www.baidu.com/',proxies={'http':'27.46.20.226:8888',})
# print(respone.text)
# 11 超时设置
# import requests
# respone=requests.get('https://www.baidu.com',
# timeout=0.0001)
# 12 认证设置（你见不到了）
# import requests
# r=requests.get('xxx',auth=('user','password'))
# print(r.status_code)
# 13 异常处理
# import requests
# from requests.exceptions import * #可以查看requests.exceptions获取异常类型
#
# try:
# r=requests.get('http://www.baidu.com',timeout=0.00001)
# # except ReadTimeout:
# # print('===:')
# except Exception as e:
# print(e)
# 14 上传文件
# res=requests.post('http://127.0.0.1:8000/index/',files={'myfile':open('a.jpg','rb')})
# print(res.text)
```
## 4 模拟登陆某网站
```python
#http://www.aa7a.cn/
import requests
session=requests.session()
data = {
'username': '616564099@qq.com',
'password': 'lqz123',
'captcha': 'zdu4',
'remember': 1,
'ref': 'http://www.aa7a.cn/user.php?act=logout',
'act': 'act_login',
}
rest = session.post('http://www.aa7a.cn/user.php',data=data)
print(rest.text)
# 拿到cookie
cookie=rest.cookies
print(cookie)
# 携带着cookies，表示登录了，页面中会有我们的用户信息616564099@qq.com
rest1=session.get('http://www.aa7a.cn/index.php')
# rest1=requests.get('http://www.aa7a.cn/index.php')
print('616564099@qq.com' in rest1.text)
```
## 5 爬取梨视频
```python
#https://www.pearvideo.com/
# 爬取梨视频
import requests
import re
res=requests.get('https://www.pearvideo.com/category_loading.jsp?reqType=5&categoryId=1&start=0')
# print(res.text)
re_video='<a href="(.*?)" class="vervideo-lilink actplay">'
video_urls=re.findall(re_video,res.text)
# https://www.pearvideo.com/
# print(video_urls)
for video in video_urls:
url='https://www.pearvideo.com/'+video
print(url)
# 向视频详情发送get请求
res_video=requests.get(url)
# print(res_video.text)
# break
re_video_mp4='hdUrl="",sdUrl="",ldUrl="",srcUrl="(.*?)",vdoUrl=srcUrl,skinRes'
video_url=re.findall(re_video_mp4,res_video.text)[0]
print(video_url)
video_name=video_url.rsplit('/',1)[-1]
print(video_name)
res_video_content=requests.get(video_url)
with open(video_name,'wb') as f:
for line in res_video_content.iter_content():
f.write(line)
```