python网络爬虫与信息提取mooc------爬取实例

实例一--爬取页面

import requests
url="https//itemjd.com/2646846.html"
try:
  r=requests.get(url)
  r.raise_for_status()
  r.encoding=r.apparent_encoding
  print(r.text[:1000])
except:
  print("爬取失败")

正常页面爬取

实例二--爬取页面

import requests
url="https://www.amazon.cn/gp/product/B01M8L5Z3Y"
try:
   kv={'user-agent':'Mozilla/5.0'}
   r=requests.get(url,headers=kv)
   r.raise_for_status()
   r.encoding=r.apparent_encoding
   print(r.text[1000:2000])
except:
   print("爬取失败")

对访问用户名有限制，模拟浏览器对网站请求

实例三--爬取搜索引擎

#百度的关键词接口：http://www.baidu.com/s?wd=keyword
#360的关键词接口：http://www.so.com/s?q=keyword
import requests
keyword="python"
try:
    kv={'wd':keyword}
    r=requests.get("http://www.baidu.com/s",params=kv)
    print(r.request.url)
    r.raise_for_status()
    print(len(r.text))
except:
    print("爬取失败")
--------------------------------------------------

import requests
keyword="python"
try:
    kv={'q':keyword}
    r=requests.get("http://www.so.com/s",params=kv)
    print(r.request.url)
    r.raise_for_status()
    print(len(r.text))
except:
    print("爬取失败")

实例四--:爬取图片

import requests
import os
url="http://image.nationalgeographic.com.cn/2017/0211/20170211061910157.jpg"
root="F://pics//"
path=root+url.split('/')[-1]
try:
    if not os.path.exists(root):
        os.mkdir(root)
    if not os.path.exists(path):
        r=requests.get(url)
        with open(path,'wb') as f:
            f.write(r.content)
            f.close()
            print("文件保存成功")
    else:
        print("文件已经存在")
except:
    print("爬取失败")

爬取并保存图片

实例五--IP地址归属地查询：

http://m.ip138.com/ip.asp?ip=ipaddress

url="http://www.ip138.com/iplookup.asp?ip="
try:
    r=requests.get(url+'202.204.80.112'+'&action=2')
    r.raise_for_status()
    r.encoding=r.apparent_encoding
    print(r.text[-500:])
except:
    print("爬取失败")

有反爬了