标签：处理 信息 style web read 参数 blog wow warnings
requests是python实现的简单易用的HTTP库，使用起来比urllib简洁很多
因为是第三方库，所以使用前需要cmd安装
pip install requests
安装完成后import一下，正常则说明可以开始使用了。
基本用法：
requests.get()用于请求目标网站，类型是一个HTTPresponse类型
import requests response = requests.get(‘http://www.baidu.com‘)
print(response.status_code) # 打印状态码
print(response.url) # 打印请求url
print(response.headers) # 打印头信息
print(response.cookies) # 打印cookie信息 print(response.text) #以文本形式打印网页源码
print(response.content) #以字节流形式打印
运行结果：
状态码：200
url：www.baidu.com
headers信息
各种请求方式：
import requests requests.get(‘http://httpbin.org/get‘) 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‘)
基本的get请求
import requests response = requests.get(‘http://httpbin.org/get‘) print(response.text)
结果
带参数的GET请求：
第一种直接将参数放在url内
import requests response = requests.get(http://httpbin.org/get?name=gemey&age=22) print(response.text)
结果
另一种先将参数填写在dict中，发起请求时params参数指定为dict
import requests data = { ‘name‘: ‘tom‘, ‘age‘: 20 } response = requests.get(‘http://httpbin.org/get‘, params=data) print(response.text)
结果同上
解析json
import requests response = requests.get(‘http://httpbin.org/get‘) print(response.text) print(response.json()) #response.json()方法同json.loads(response.text) print(type(response.json()))
结果
简单保存一个二进制文件
二进制内容为response.content
import requests response = requests.get(‘http://img.ivsky.com/img/tupian/pre/201708/30/kekeersitao-002.jpg‘) b = response.content with open(‘F://fengjing.jpg‘,‘wb‘) as f: f.write(b)
为你的请求添加头信息
import requests
heads = {}
heads[‘User-Agent‘] = ‘Mozilla/5.0 ‘ \
‘(Macintosh; U; Intel Mac OS X 10_6_8; en-us) AppleWebKit/534.50 ‘ \
‘(KHTML, like Gecko) Version/5.1 Safari/534.50‘
response = requests.get(‘http://www.baidu.com‘,headers=headers)
使用代理
同添加headers方法，代理参数也要是一个dict
这里使用requests库爬取了IP代理网站的IP与端口和类型
因为是免费的，使用的代理地址很快就失效了。
import requests import re def get_html(url): proxy = { ‘http‘: ‘120.25.253.234:812‘, ‘https‘ ‘163.125.222.244:8123‘ } heads = {} heads[‘User-Agent‘] = ‘Mozilla/5.0 (Windows NT 10.0; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/49.0.2623.221 Safari/537.36 SE 2.X MetaSr 1.0‘ req = requests.get(url, headers=heads,proxies=proxy) html = req.text return html def get_ipport(html): regex = r‘<td data-title="IP">(.+)</td>‘ iplist = re.findall(regex, html) regex2 = ‘<td data-title="PORT">(.+)</td>‘ portlist = re.findall(regex2, html) regex3 = r‘<td data-title="类型">(.+)</td>‘ typelist = re.findall(regex3, html) sumray = [] for i in iplist: for p in portlist: for t in typelist: pass pass a = t+‘,‘+i + ‘:‘ + p sumray.append(a) print(‘高匿代理‘) print(sumray) if __name__ == ‘__main__‘: url = ‘http://www.kuaidaili.com/free/‘ get_ipport(get_html(url))
结果：
基本POST请求：
import requests data = {‘name‘:‘tom‘,‘age‘:‘22‘} response = requests.post(‘http://httpbin.org/post‘, data=data)
获取cookie
#获取cookie import requests response = requests.get(‘http://www.baidu.com‘) print(response.cookies) print(type(response.cookies)) for k,v in response.cookies.items(): print(k+‘:‘+v)
结果：
会话维持
import requests session = requests.Session() session.get(‘http://httpbin.org/cookies/set/number/12345‘) response = session.get(‘http://httpbin.org/cookies‘) print(response.text)
结果：
证书验证设置
import requests from requests.packages import urllib3 urllib3.disable_warnings() #从urllib3中消除警告 response = requests.get(‘https://www.12306.cn‘,verify=False) #证书验证设为FALSE print(response.status_code)
打印结果：200
超时异常捕获
import requests from requests.exceptions import ReadTimeout try: res = requests.get(‘http://httpbin.org‘, timeout=0.1) print(res.status_code) except ReadTimeout: print(timeout)
异常处理
在你不确定会发生什么错误时，尽量使用try...except来捕获异常
所有的requests exception：
import requests from requests.exceptions import ReadTimeout,HTTPError,RequestException try: response = requests.get(‘http://www.baidu.com‘,timeout=0.5) print(response.status_code) except ReadTimeout: print(‘timeout‘) except HTTPError: print(‘httperror‘) except RequestException: print(‘reqerror‘)
标签：处理 信息 style web read 参数 blog wow warnings
原文地址：http://www.cnblogs.com/mzc1997/p/7813801.html
