python爬虫

python如何访问互联网 url+lib==urllib

　　url protocol://hostname[:port]/path/[;parameters][?query][#fragement]

　　protocol:http https ftp file ed2k 服务器域名/ip  资源地址

urllib(包 四个模块 urllib.request urllib.error urllib.parse urllib.robotparer)

　　rullib.request.urlopen(url,data,timeout,capath...)

import urllib.request

response = rullib.request.urlopen('http://www.baidu.com')
html = response.read() #二进制
html= html.decode("utf-8")
print(html)

#下载一只猫 placekitten.com
import urllib.request

reponse = urllib.request.urlopen('placekitten.com/g/500/600')
#req = urllib.request.Request('placekitten.com/g/500/600')
#response = req.urlopen(req)

response.geturl()
response.info()
response.getcode()

cat_img = response.read()
with open('cat_500_600.jpg',’wb') as f:
    f.write(cat_img)

　　

#有道翻译
#network Method(GET POST) preview
#Headers 
    #Remote Address: Request URL: Request Method:
    #Request Headers(客户端发送请求的header User-Agent是否非人类访问)
    #Form Data:
#隐藏 检查headers > user agent
#ip访问频率 1减少频率 2使用代理
import urllib.request
import urllib.parse
import json
import time

while True:

　　content = input("请输入需要翻译的内容（输入'q!'退出程序）")
　　if content == 'q!'
　　　　break
　　url = "http://fanyi.youdao.com..."
　　data = {}
　　data['type'] = 'AUTO'
　　data['i'] ='i love'
　　data['doctype'] = 'json'
　　data['xmlVersion'] = '1.6'
　　data['keyfrom'] = content
　　data['ue'] = 'UTF-8'
　　data['typoResult'] = 'true'

　　data = urllib.parse.urlencode(data).encode('utf-8')

　　'''1
　　head = {}
　　head['User-Agent'] = 'Mozilla/5.0...'
　　response = urllib.request.urlopen(url, data, head)
　　'''

　　req = urllib.request.Request(url,data)
　　req.add_header('User-agent','Mozilla/5.0')
   '''代理
　　1参数是一个字典{'类型':'代理ip:端口号'}
　　　proxy_support =urllib.request.ProxyHandler({})
　　2定制创建一个opener
　　 opener = urllib.request.build_opener(proxy_support)
   3a安装opener urllib.request.install_opener(opener)
   3b调用opner opener.open(url)
　　'''
　　html = req.read().decode('utf-8')
　　#json轻量级数据交换格式
　　target = json.loads(html)
　　#type(target) dict

　　print("翻译结果:"+target['translateResult'][0][0]['tgt'])
　　time.sleep(5)

#测试代理
import urllib.request
import random

url = 'http://www.whatismyip.com.tw'
ip_list = ['','','']

proxy_support = urllib.request.ProxyHandler({'http':random.choice(iplist)})
opener = urllib.request.build_opener(proxy_support)
opener.addheaders = [('User-Agent':'Mozzilla')]

urllib.request.install_opener(open)
response = urllib.request.urlopen(url)
html = response.read().decode('utf-8')