两天时间写了个爬虫，问题多多

 

1.正则表达式考虑不完整，数据出现浮点数，整数，没有都有可能，正则表达式不规范要么取不到数据，要么取到错误的数据，

由于没有及时检查，导致整个攻击增加没有取到，简直是严重失误，不过也只能这样了

2. python  版本更替，2.7和3.3 差别太多，内部编码方式和整个urllib库 都有很多改动，导致网上代码参考价值较小，给整个变成过程造成了阻碍

等发现这个问题的时候，基本代码已经写完，再改也来不及了

3.事先调研不清楚，LOL数据在很多网站都有，开始写爬虫的时候并没有调查多个网站，而是随便选了一个178作为爬取网站，结果遇到了反爬虫系统（估计是），如果多调查几个网站，说不定能事半功倍。

4.没有反爬虫的意识，对HTTP协议的理解也不够深刻

下次值得改善，加入浏览器头文件，伪造访问

 

http://www.cnblogs.com/txw1958/archive/2011/12/21/2295698.html

urllib3.3的常用函数 

1、最简单

import urllib.request response = urllib.request.urlopen('http://python.org/') html = response.read()

2、使用 Request

import urllib.request req = urllib.request.Request('http://python.org/') response = urllib.request.urlopen(req) the_page = response.read()

 

3、发送数据

#! /usr/bin/env python3  import urllib.parse import urllib.request url = 'http://localhost/login.php' user_agent = 'Mozilla/4.0 (compatible; MSIE 5.5; Windows NT)' values = {
    'act' : 'login', 'login[email]' : 'yzhang@i9i8.com', 'login[password]' : '123456'          } data = urllib.parse.urlencode(values) req = urllib.request.Request(url, data) req.add_header('Referer', 'http://www.python.org/') response = urllib.request.urlopen(req) the_page = response.read() print(the_page.decode("utf8"))

 

4、发送数据和header

#! /usr/bin/env python3  import urllib.parse import urllib.request url = 'http://localhost/login.php' user_agent = 'Mozilla/4.0 (compatible; MSIE 5.5; Windows NT)' values = {
    'act' : 'login', 'login[email]' : 'yzhang@i9i8.com', 'login[password]' : '123456'          } headers = { 'User-Agent' : user_agent } data = urllib.parse.urlencode(values) req = urllib.request.Request(url, data, headers) response = urllib.request.urlopen(req) the_page = response.read() print(the_page.decode("utf8"))

 

5、http 错误

#! /usr/bin/env python3  import urllib.request req = urllib.request.Request('http://www.python.org/fish.html') try:     urllib.request.urlopen(req) except urllib.error.HTTPError as e: print(e.code) print(e.read().decode("utf8"))

 

6、异常处理1

#! /usr/bin/env python3  from urllib.request import Request, urlopen from urllib.error import URLError, HTTPError req = Request("http://twitter.com/") try:     response = urlopen(req) except HTTPError as e: print('The server couldn\'t fulfill the request.') print('Error code: ', e.code) except URLError as e: print('We failed to reach a server.') print('Reason: ', e.reason) else: print("good!") print(response.read().decode("utf8"))

 

7、异常处理2

#! /usr/bin/env python3  from urllib.request import Request, urlopen from urllib.error import  URLError req = Request("http://twitter.com/") try:     response = urlopen(req) except URLError as e: if hasattr(e, 'reason'): print('We failed to reach a server.') print('Reason: ', e.reason) elif hasattr(e, 'code'): print('The server couldn\'t fulfill the request.') print('Error code: ', e.code) else: print("good!") print(response.read().decode("utf8"))

 

8、HTTP 认证

#! /usr/bin/env python3  import urllib.request # create a password manager password_mgr = urllib.request.HTTPPasswordMgrWithDefaultRealm() # Add the username and password. # If we knew the realm, we could use it instead of None. top_level_url = "https://cms.tetx.com/" password_mgr.add_password(None, top_level_url, 'yzhang', 'cccddd') handler = urllib.request.HTTPBasicAuthHandler(password_mgr) # create "opener" (OpenerDirector instance) opener = urllib.request.build_opener(handler) # use the opener to fetch a URL a_url = "https://cms.tetx.com/" x = opener.open(a_url) print(x.read()) # Install the opener. # Now all calls to urllib.request.urlopen use our opener. urllib.request.install_opener(opener) a = urllib.request.urlopen(a_url).read().decode('utf8') print(a)

 

9、使用代理

#! /usr/bin/env python3  import urllib.request proxy_support = urllib.request.ProxyHandler({
     'sock5': 'localhost:1080'}) opener = urllib.request.build_opener(proxy_support) urllib.request.install_opener(opener) a = urllib.request.urlopen("http://g.cn").read().decode("utf8") print(a)

 

10、超时

#! /usr/bin/env python3  import socket import urllib.request # timeout in seconds timeout = 2 socket.setdefaulttimeout(timeout) # this call to urllib.request.urlopen now uses the default timeout # we have set in the socket module req = urllib.request.Request('http://twitter.com/') a = urllib.request.urlopen(req).read() print(a)