python爬虫---requests库的用法详解

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

python爬虫---requests库的用法详解

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

python爬虫---requests库的用法详解

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

python爬虫---requests库的用法详解

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 = http://www.cppcns.com/jiaoben/python/{'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

python爬虫---requests库的用法详解

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:

python爬虫---requests库的用法详解

基本POST请求:

python爬虫---requests库的用法详解

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