简介
Requests是用python语言基于urllib编写的,采用的是Apache2 Licensed开源协议的HTTP库,Requests它会比urllib更加方便,可以节约我们大量的工作。
一、安装
pip快速安装
二、使用
1、先上一串代码
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import requests
response = requests.get( "https://www.baidu.com" )
print ( type (response))
print (response.status_code)
print ( type (response.text))
response.enconding = "utf - 8 ‘
print (response.text)
print (response.cookies)
print (response.content)
print (response.content.decode( "utf-8" ))
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response.text返回的是Unicode格式,通常需要转换为utf-8格式,否则就是乱码。response.content是二进制模式,可以下载视频之类的,如果想看的话需要decode成utf-8格式。
不管是通过response.content.decode("utf-8)的方式还是通过response.encoding="utf-8"的方式都可以避免乱码的问题发生
2、一大推请求方式
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import requests
requests.post( "http://httpbin.org/post" )
requests.put( "http://httpbin.org/put" )
requests.delete( "http://httpbin.org/delete" )
requests.head( "http://httpbin.org/get" )
requests.options( "http://httpbin.org/get" )
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基本GET:
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import requests
url = ‘https://www.baidu.com/‘
response = requests.get(url)
print (response.text)
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带参数的GET请求:
如果想查询http://httpbin.org/get页面的具体参数,需要在url里面加上,例如我想看有没有Host=httpbin.org这条数据,url形式应该是http://httpbin.org/get?Host=httpbin.org
下面提交的数据是往这个地址传送data里面的数据。
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import requests
url = ‘http://httpbin.org/get‘
data = {
‘name‘ : ‘zhangsan‘ ,
‘age‘ : ‘25‘
}
response = requests.get(url,params = data)
print (response.url)
print (response.text)
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Json数据:
从下面的数据中我们可以得出,如果结果:
1、requests中response.json()方法等同于json.loads(response.text)方法
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import requests
import json
response = requests.get( "http://httpbin.org/get" )
print ( type (response.text))
print (response.json())
print (json.loads(response.text))
print ( type (response.json())
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获取二进制数据
在上面提到了response.content,这样获取的数据是二进制数据,同样的这个方法也可以用于下载图片以及
视频资源
添加header
首先说,为什么要加header(头部信息)呢?例如下面,我们试图访问知乎的登录页面(当然大家都你要是不登录知乎,就看不到里面的内容),我们试试不加header信息会报什么错。
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import requests
url = ‘https://www.zhihu.com/‘
response = requests.get(url)
response.encoding = "utf-8"
print (response.text)
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结果:
提示发生内部服务器错误(也就说你连知乎登录页面的html都下载不下来)。
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<html><body><h1> 500 Server Error< / h1>
An internal server error occured.
< / body>< / html>
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如果想访问就必须得加headers信息。
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import requests
url = ‘https://www.zhihu.com/‘
headers = {
‘User-Agent‘ : ‘Mozilla/5.0 (Windows NT 10.0; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/57.0.2987.133 Safari/537.36‘
}
response = requests.get(url,headers = headers)
print (response.text)
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基本post请求:
通过post把数据提交到url地址,等同于一字典的形式提交form表单里面的数据
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import requests
url = ‘http://httpbin.org/post‘
data = {
‘name‘ : ‘jack‘ ,
‘age‘ : ‘23‘
}
response = requests.post(url,data = data)
print (response.text)
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结果:
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{
"args" : {},
"data" : "",
"files" : {},
"form" : {
"age" : "23" ,
"name" : "jack"
},
"headers" : {
"Accept" : "*/*" ,
"Accept-Encoding" : "gzip, deflate" ,
"Connection" : "close" ,
"Content-Length" : "16" ,
"Content-Type" : "application/x-www-form-urlencoded" ,
"Host" : "httpbin.org" ,
"User-Agent" : "python-requests/2.13.0"
},
"json" : null,
"origin" : "118.144.137.95" ,
"url" : "http://httpbin.org/post"
}
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响应:
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import requests
response = requests.get( "http://www.baidu.com" )
#打印请求页面的状态(状态码)
print ( type (response.status_code),response.status_code)
#打印请求网址的headers所有信息
print ( type (response.headers),response.headers)
#打印请求网址的cookies信息
print ( type (response.cookies),response.cookies)
#打印请求网址的地址
print ( type (response.url),response.url)
#打印请求的历史记录(以列表的形式显示)
print ( type (response.history),response.history)
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内置的状态码:
内置的状态码
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import requests
response = requests.get( ‘http://www.jianshu.com/404.html‘ )
# 使用request内置的字母判断状态码
#如果response返回的状态码是非正常的就返回404错误
if response.status_code ! = requests.codes.ok:
print ( ‘404‘ )
#如果页面返回的状态码是200,就打印下面的状态
response = requests.get( ‘http://www.jianshu.com‘ )
if response.status_code = = 200 :
print ( ‘200‘ )
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request的高级操作
文件上传
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import requests
url = "http://httpbin.org/post"
files = { "files" : open ( "test.jpg" , "rb" )}
response = requests.post(url,files = files)
print (response.text)
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结果:
获取cookie
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import requests
response = requests.get( ‘https://www.baidu.com‘ )
print (response.cookies)
for key,value in response.cookies.items():
print (key, ‘==‘ ,value)
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会话维持
cookie的一个作用就是可以用于模拟登陆,做会话维持
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import requests
session = requests.session()
session.get( ‘http://httpbin.org/cookies/set/number/12456‘ )
response = session.get( ‘http://httpbin.org/cookies‘ )
print (response.text)
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证书验证
1、无证书访问
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import requests
response = requests.get( ‘https://www.12306.cn‘ )
# 在请求https时,request会进行证书的验证,如果验证失败则会抛出异常
print (response.status_code)
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报错:
关闭证书验证
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import requests
# 关闭验证,但是仍然会报出证书警告
response = requests.get( ‘https://www.12306.cn‘ ,verify = False )
print (response.status_code)
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为了避免这种情况的发生可以通过verify=False,但是这样是可以访问到页面结果
消除验证证书的警报
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from requests.packages import urllib3
import requests
urllib3.disable_warnings()
response = requests.get( ‘https://www.12306.cn‘ ,verify = False )
print (response.status_code)
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手动设置证书
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import requests
response = requests.get( ‘https://www.12306.cn‘ , cert = ( ‘/path/server.crt‘ , ‘/path/key‘ ))
print (response.status_code)
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代理设置
1、设置普通代理
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import requests
proxies = {
"http" : "http://127.0.0.1:9743" ,
"https" : "https://127.0.0.1:9743" ,
}
response = requests.get( "https://www.taobao.com" , proxies = proxies)
print (response.status_code)
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2、设置用户名和密码代理
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import requests
proxies = {
"http" : "http://user:[email protected]:9743/" ,
}
response = requests.get( "https://www.taobao.com" , proxies = proxies)
print (response.status_code)
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设置socks代理
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安装socks模块 pip3 install ‘requests[socks]‘
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import requests
proxies = {
‘http‘ : ‘socks5://127.0.0.1:9742‘ ,
‘https‘ : ‘socks5://127.0.0.1:9742‘
}
response = requests.get( "https://www.taobao.com" , proxies = proxies)
print (response.status_code)
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超时设置
通过timeout参数可以设置超时的时间
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import requests
from requests.exceptions import ReadTimeout
try :
# 设置必须在500ms内收到响应,不然或抛出ReadTimeout异常
response = requests.get( "http://httpbin.org/get" , timeout = 0.5 )
print (response.status_code)
except ReadTimeout:
print ( ‘Timeout‘ )
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认证设置
如果碰到需要认证的网站可以通过requests.auth模块实现
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import requests
from requests.auth import HTTPBasicAuth
<br> #方法一
r = requests.get( ‘http://120.27.34.24:9001‘ , auth = HTTPBasicAuth( ‘user‘ , ‘123‘ ))<br>
#方法二<br>r = requests.get(‘http://120.27.34.24:9001‘, auth=(‘user‘, ‘123‘))
print (r.status_code)
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异常处理
关于reqeusts的异常在这里可以看到详细内容:
http://www.python-requests.org/en/master/api/#exceptions
所有的异常都是在requests.excepitons中
从源码我们可以看出RequestException继承IOError,
HTTPError,ConnectionError,Timeout继承RequestionException
ProxyError,SSLError继承ConnectionError
ReadTimeout继承Timeout异常
这里列举了一些常用的异常继承关系,详细的可以看:
http://cn.python-requests.org/zh_CN/latest/_modules/requests/exceptions.html#RequestException
通过下面的例子进行简单的演示
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import requests
from requests.exceptions import ReadTimeout, ConnectionError, RequestException
try :
response = requests.get( "http://httpbin.org/get" , timeout = 0.5 )
print (response.status_code)
except ReadTimeout:
print ( ‘Timeout‘ )
except ConnectionError:
print ( ‘Connection error‘ )
except RequestException:
print ( ‘Error‘ )
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首先被捕捉的异常是timeout,当把网络断掉的haul就会捕捉到ConnectionError,如果前面异常都没有捕捉到,最后也可以通过RequestExctption捕捉到
原文地址:https://www.cnblogs.com/peter200-OK/p/9058469.html
时间: 2024-11-05 16:05:39