1、常用库-Request
1.1、 介绍
#安装:pip3 install requests
#各种请求方式:常用的就是requests.get()和requests.post()
>>> import requests
>>> r = requests.get('https://api.github.com/events')
>>> r = requests.post('http://httpbin.org/post', data = {'key':'value'})
>>> r = requests.put('http://httpbin.org/put', data = {'key':'value'})
>>> r = requests.delete('http://httpbin.org/delete')
>>> r = requests.head('http://httpbin.org/get')
>>> r = requests.options('http://httpbin.org/get')
1.2、基于GET请求
- 1、基本请求
import requests
response=requests.get('http://dig.chouti.com/')
print(response.text)
- 2、带参数的GET请求->params
import requests
response=requests.get('https://www.baidu.com')
response = requests.get(url='http://dict.baidu.com/s', params={'wd': 'python'}) # 带参数的get请求
- 3、带参数的GET请求->headers
#通常我们在发送请求时都需要带上请求头,请求头是将自身伪装成浏览器的关键,常见的有用的请求头如下
Host
Referer #大型网站通常都会根据该参数判断请求的来源
User-Agent #客户端
Cookie #Cookie信息虽然包含在请求头里,但requests模块有单独的参数来处理他,headers={}内就不要放它了
#添加headers(浏览器会识别请求头,不加可能会被拒绝访问,比如访问https://www.zhihu.com/explore)
import requests
response=requests.get('https://www.zhihu.com/explore')
response.status_code #500
#自己定制headers
headers={
'User-Agent':'Mozilla/5.0 (Linux; Android 6.0; Nexus 5 Build/MRA58N) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/46.0.2490.76 Mobile Safari/537.36',
}
respone=requests.get('https://www.zhihu.com/explore',
headers=headers)
print(respone.status_code) #200
- 4、带参数的GET请求->cookies
import uuid
import requests
url = 'http://httpbin.org/cookies'
cookies = dict(sbid=str(uuid.uuid4()))
res = requests.get(url, cookies=cookies)
print(res.json())
1.3、基于POST请求
- 1、介绍
#GET请求
HTTP默认的请求方法就是GET
* 没有请求体
* 数据必须在1K之内!
* GET请求数据会暴露在浏览器的地址栏中
GET请求常用的操作:
1. 在浏览器的地址栏中直接给出URL,那么就一定是GET请求
2. 点击页面上的超链接也一定是GET请求
3. 提交表单时,表单默认使用GET请求,但可以设置为POST
#POST请求
(1). 数据不会出现在地址栏中
(2). 数据的大小没有上限
(3). 有请求体
(4). 请求体中如果存在中文,会使用URL编码!
#!!!requests.post()用法与requests.get()完全一致,特殊的是requests.post()有一个data参数,用来存放请求体数据
- 2、发送post请求,模拟浏览器的登录行为
- 一 目标站点分析
浏览器输入https://github.com/login
然后输入错误的账号密码,抓包
发现登录行为是post提交到:https://github.com/session
而且请求头包含cookie
而且请求体包含:
commit:Sign in
utf8:✓
authenticity_token:lbI8IJCwGslZS8qJPnof5e7ZkCoSoMn6jmDTsL1r/m06NLyIbw7vCrpwrFAPzHMep3Tmf/TSJVoXWrvDZaVwxQ==
login:maple
password:123
- 二 流程分析
先GET:https://github.com/login拿到初始cookie与authenticity_token
返回POST:https://github.com/session, 带上初始cookie,带上请求体(authenticity_token,用户名,密码等)
最后拿到登录cookie
ps:如果密码时密文形式,则可以先输错账号,输对密码,然后到浏览器中拿到加密后的密码,github的密码是明文
'''
import requests
import re
#第一次请求
r1=requests.get('https://github.com/login')
r1_cookie=r1.cookies.get_dict() #拿到初始cookie(未被授权)
authenticity_token=re.findall(r'name="authenticity_token".*?value="(.*?)"',r1.text)[0] #从页面中拿到CSRF TOKEN
#第二次请求:带着初始cookie和TOKEN发送POST请求给登录页面,带上账号密码
data={
'commit':'Sign in',
'utf8':'✓',
'authenticity_token':authenticity_token,
'login':'maple@qq.com',
'password':'123'
}
r2=requests.post('https://github.com/session',
data=data,
cookies=r1_cookie
)
login_cookie=r2.cookies.get_dict()
#第三次请求:以后的登录,拿着login_cookie就可以,比如访问一些个人配置
r3=requests.get('https://github.com/settings/emails',
cookies=login_cookie)
print('maple@qq.com' in r3.text) #True
自动登录Github(自己处理cookie信息)
import requests
import re
session=requests.session()
#第一次请求
r1=session.get('https://github.com/login')
authenticity_token=re.findall(r'name="authenticity_token".*?value="(.*?)"',r1.text)[0] #从页面中拿到CSRF TOKEN
#第二次请求
data={
'commit':'Sign in',
'utf8':'✓',
'authenticity_token':authenticity_token,
'login':'maple@qq.com',
'password':'123'
}
r2=session.post('https://github.com/session',
data=data,
)
#第三次请求
r3=session.get('https://github.com/settings/emails')
print('maple@qq.com' in r3.text) #True
requests.session()自动帮我们保存cookie信息
1.4、补充
requests.post(url='xxxxxxxx',
data={'xxx':'yyy'}) #没有指定请求头,#默认的请求头:application/x-www-form-urlencoed
#如果我们自定义请求头是application/json,并且用data传值, 则服务端取不到值
requests.post(url='',
data={'':1,},
headers={
'content-type':'application/json'
})
requests.post(url='',
json={'':1,},
) #默认的请求头:application/json
1.5、响应Response
- 1、response属性
import requests
respone=requests.get('http://www.jianshu.com')
# respone属性
#获取所有内容
print(respone.text)
#获取二进制
print(respone.content)
#获取状态码,如200,301等
print(respone.status_code)
print(respone.headers)
print(respone.cookies)
#获取cookie
print(respone.cookies.get_dict())
print(respone.cookies.items())
print(respone.url)
print(respone.history)
#获取编码
print(respone.encoding)
#解决乱码
print(response.apparent_encoding)
- 2、编码问题
#编码问题
import requests
response=requests.get('http://www.autohome.com/news')
#方式一:
# response.encoding='gbk' #汽车之家网站返回的页面内容为gb2312编码的,而requests的默认编码为ISO-8859-1,如果不设置成gbk则中文乱码
print(response.text)
#方式二:
#在不知道编码格式的前提下使用以下方式
response.encoding=response.apparent_encoding
print(response.text)
- 3、获取二进制数据
import requests
response=requests.get('https://timgsa.baidu.com/timg?image&quality=80&size=b9999_10000&sec=1509868306530&di=712e4ef3ab258b36e9f4b48e85a81c9d&imgtype=0&src=http%3A%2F%2Fc.hiphotos.baidu.com%2Fimage%2Fpic%2Fitem%2F11385343fbf2b211e1fb58a1c08065380dd78e0c.jpg')
with open('a.jpg','wb') as f:
f.write(response.content)
- 4、解析json
#解析json
import requests
response=requests.get('http://httpbin.org/get')
import json
res1=json.loads(response.text) #太麻烦
res2=response.json() #直接获取json数据
print(res1 == res2) #True
1.6、高级用法
- 1、SSL Cert Verification
#证书验证(大部分网站都是https)
import requests
# 如果是ssl请求,首先检查证书是否合法,不合法则报错,程序终端
response = requests.get('https://www.xiaohuar.com')
print(response.status_code)
# 改进1:去掉报错,但是会报警告
import requests
response = requests.get('https://www.xiaohuar.com', verify=False)
# 不验证证书,报警告,返回200
print(response.status_code)
# 改进2:去掉报错,并且去掉警报信息
import requests
import urllib3
urllib3.disable_warnings() # 关闭警告
response = requests.get('https://www.xiaohuar.com', verify=False)
print(response.status_code)
# 改进3:加上证书
# 很多网站都是https,但是不用证书也可以访问,大多数情况都是可以携带也可以不携带证书
# 知乎\百度等都是可带可不带
# 有硬性要求的,则必须带,比如对于定向的用户,拿到证书后才有权限访问某个特定网站
import requests
import urllib3
# urllib3.disable_warnings() # 关闭警告
response = requests.get(
'https://www.xiaohuar.com',
# verify=False,
cert=('/path/server.crt', '/path/key'))
print(response.status_code)
- 2、使用代理
# 官网链接: http://docs.python-requests.org/en/master/user/advanced/#proxies
# 代理设置:先发送请求给代理,然后由代理帮忙发送(封ip是常见的事情)
import requests
proxies={
# 带用户名密码的代理,@符号前是用户名与密码
'http':'http://tank:123@localhost:9527',
'http':'http://localhost:9527',
'https':'https://localhost:9527',
}
response=requests.get('https://www.12306.cn',
proxies=proxies)
print(response.status_code)
# 支持socks代理,安装:pip install requests[socks]
import requests
proxies = {
'http': 'socks5://user:pass@host:port',
'https': 'socks5://user:pass@host:port'
}
respone=requests.get('https://www.12306.cn',
proxies=proxies)
print(respone.status_code)
使用代理爬取微信新闻: 参考
from urllib.parse import urlencode
import pymongo
import requests
from lxml.etree import XMLSyntaxError
from requests.exceptions import ConnectionError
from pyquery import PyQuery as pq
# from config import *
#
# client = pymongo.MongoClient(MONGO_URI)
# db = client[MONGO_DB]
base_url = 'http://weixin.sogou.com/weixin?'
headers = {
'Cookie': 'SUID=F6177C7B3220910A000000058E4D679; SUV=1491392122762346; ABTEST=1|1491392129|v1; SNUID=0DED8681FBFEB69230E6BF3DFB2F8D6B; ld=OZllllllll2Yi2balllllV06C77lllllWTZgdkllll9lllllxv7ll5@@@@@@@@@@; LSTMV=189%2C31; LCLKINT=1805; weixinIndexVisited=1; SUIR=0DED8681FBFEB69230E6BF3DFB2F8D6B; JSESSIONID=aaa-BcHIDk9xYdr4odFSv; PHPSESSID=afohijek3ju93ab6l0eqeph902; sct=21; IPLOC=CN; ppinf=5|1491580643|1492790243|dHJ1c3Q6MToxfGNsaWVudGlkOjQ6MjAxN3x1bmlxbmFtZToyNzolRTUlQjQlOTQlRTUlQkElODYlRTYlODklOER8Y3J0OjEwOjE0OTE1ODA2NDN8cmVmbmljazoyNzolRTUlQjQlOTQlRTUlQkElODYlRTYlODklOER8dXNlcmlkOjQ0Om85dDJsdUJfZWVYOGRqSjRKN0xhNlBta0RJODRAd2VpeGluLnNvaHUuY29tfA; pprdig=j7ojfJRegMrYrl96LmzUhNq-RujAWyuXT_H3xZba8nNtaj7NKA5d0ORq-yoqedkBg4USxLzmbUMnIVsCUjFciRnHDPJ6TyNrurEdWT_LvHsQIKkygfLJH-U2MJvhwtHuW09enCEzcDAA_GdjwX6_-_fqTJuv9w9Gsw4rF9xfGf4; sgid=; ppmdig=1491580643000000d6ae8b0ebe76bbd1844c993d1ff47cea',
'Host': 'weixin.sogou.com',
'Upgrade-Insecure-Requests': '1',
'User-Agent': 'Mozilla/5.0 (Macintosh; Intel Mac OS X 10_12_3) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/57.0.2987.133 Safari/537.36'
}
proxy = None
def get_proxy():
try:
response = requests.get('http://127.0.0.1:5555/random')
if response.status_code == 200:
return response.text
return None
except ConnectionError:
return None
def get_html(url, count=1):
print('Crawling', url)
print('Trying Count', count)
global proxy
if count >= 5:
print('Tried Too Many Counts')
return None
try:
if proxy:
proxies = {
'http': 'http://' + proxy
}
response = requests.get(url, allow_redirects=False, headers=headers, proxies=proxies)
else:
response = requests.get(url, allow_redirects=False, headers=headers)
if response.status_code == 200:
return response.text
if response.status_code == 302:
# Need Proxy
print('302')
proxy = get_proxy()
if proxy:
print('Using Proxy', proxy)
return get_html(url)
else:
print('Get Proxy Failed')
return None
except ConnectionError as e:
print('Error Occurred', e.args)
proxy = get_proxy()
count += 1
return get_html(url, count)
def get_index(keyword, page):
data = {
'query': keyword,
'type': 2,
'page': page
}
queries = urlencode(data)
url = base_url + queries
html = get_html(url)
return html
def parse_index(html):
doc = pq(html)
items = doc('.news-box .news-list li .txt-box h3 a').items()
for item in items:
yield item.attr('href')
def get_detail(url):
try:
response = requests.get(url)
if response.status_code == 200:
return response.text
return None
except ConnectionError:
return None
def parse_detail(html):
try:
doc = pq(html)
title = doc('.rich_media_title').text()
content = doc('.rich_media_content').text()
date = doc('#post-date').text()
nickname = doc('#js_profile_qrcode > div > strong').text()
wechat = doc('#js_profile_qrcode > div > p:nth-child(3) > span').text()
return {
'title': title,
'content': content,
'date': date,
'nickname': nickname,
'wechat': wechat
}
except XMLSyntaxError:
return None
# def save_to_mongo(data):
# if db['articles'].update({'title': data['title']}, {'$set': data}, True):
# print('Saved to Mongo', data['title'])
# else:
# print('Saved to Mongo Failed', data['title'])
def main():
for page in range(1, 101):
html = get_index('Python', page)
if html:
article_urls = parse_index(html)
for article_url in article_urls:
article_html = get_detail(article_url)
if article_html:
article_data = parse_detail(article_html)
print(article_data)
# if article_data:
# save_to_mongo(article_data)
if __name__ == '__main__':
main()
- 3、超时设置
#超时设置
#两种超时:float or tuple
#timeout=0.1 #代表接收数据的超时时间
#timeout=(0.1,0.2)#0.1代表链接超时 0.2代表接收数据的超时时间
import requests
respone=requests.get('https://www.baidu.com',
timeout=0.0001)
- 4、 认证设置
# 官网链接:http://docs.python-requests.org/en/master/user/authentication/
# 认证设置:登陆网站是,弹出一个框,要求你输入用户名密码(与alter很类似),此时是无法获取html的
# ps: https://www.cnblogs.com/post/readauth?url=/kermitjam/articles/10147263.html
# 但本质原理是拼接成请求头发送
# r.headers['Authorization'] = _basic_auth_str(self.username, self.password)
# 一般的网站都不用默认的加密方式,都是自己写
# 那么我们就需要按照网站的加密方式,自己写一个类似于_basic_auth_str的方法
# 得到加密字符串后添加到请求头
# r.headers['Authorization'] =func('.....')
# 看一看默认的加密方式吧,通常网站都不会用默认的加密设置
import requests
from requests.auth import HTTPBasicAuth
r=requests.get('xxx',auth=HTTPBasicAuth('user','password'))
print(r.status_code)
# HTTPBasicAuth可以简写为如下格式
import requests
r=requests.get('xxx',auth=('user','password'))
print(r.status_code)
- 5、异常处理
#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 ConnectionError: #网络不通
# print('-----')
# except Timeout:
# print('aaaaa')
except RequestException:
print('Error')
- 6、上传文件
import requests
files={'file':open('a.jpg','rb')}
respone=requests.post('http://httpbin.org/post',files=files)
print(respone.status_code)