Python爬虫抓取csdn博客

Python爬虫抓取csdn博客

昨天晚上为了下载保存某位csdn大牛的全部博文，写了一个爬虫来自动抓取文章并保存到txt文本，当然也可以 保存到html网页中。这样就可以不用Ctrl+C 和Ctrl+V了，非常方便，抓取别的网站也是大同小异。
为了解析抓取的网页，用到了第三方模块，BeautifulSoup，这个模块对于解析html文件非常有用，当然也可以自己使用正则表达式去解析，但是比较麻烦。
由于csdn网站的robots.txt文件中显示禁止任何爬虫，所以必须把爬虫伪装成浏览器，而且不能频繁抓取，得sleep一会再抓，使用频繁会被封ip的，但可以使用代理ip。

#-*- encoding: utf-8 -*-
'''
Created on 2014-09-18 21:10:39

@author: Mangoer
@email: 2395528746@qq.com
'''

import urllib2
import re
from bs4 import BeautifulSoup
import random
import time

class CSDN_Blog_Spider:
def __init__(self,url):

print '\n'
print('已启动网络爬虫。。。')
print  '网页地址： ' + url

user_agents = [
'Mozilla/5.0 (Windows; U; Windows NT 5.1; it; rv:1.8.1.11) Gecko/20071127 Firefox/2.0.0.11',
'Opera/9.25 (Windows NT 5.1; U; en)',
'Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; SV1; .NET CLR 1.1.4322; .NET CLR 2.0.50727)',
'Mozilla/5.0 (compatible; Konqueror/3.5; Linux) KHTML/3.5.5 (like Gecko) (Kubuntu)',
'Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.8.0.12) Gecko/20070731 Ubuntu/dapper-security Firefox/1.5.0.12',
'Lynx/2.8.5rel.1 libwww-FM/2.14 SSL-MM/1.4.1 GNUTLS/1.2.9',
"Mozilla/5.0 (X11; Linux i686) AppleWebKit/535.7 (KHTML, like Gecko) Ubuntu/11.04 Chromium/16.0.912.77 Chrome/16.0.912.77 Safari/535.7",
"Mozilla/5.0 (X11; Ubuntu; Linux i686; rv:10.0) Gecko/20100101 Firefox/10.0 ",
]
# use proxy ip
# ips_list = ['60.220.204.2:63000','123.150.92.91:80','121.248.150.107:8080','61.185.21.175:8080','222.216.109.114:3128','118.144.54.190:8118',
#           '1.50.235.82:80','203.80.144.4:80']

# ip = random.choice(ips_list)
# print '使用的代理ip地址： ' + ip

# proxy_support = urllib2.ProxyHandler({'http':'http://'+ip})
# opener = urllib2.build_opener(proxy_support)
# urllib2.install_opener(opener)

agent = random.choice(user_agents)

req = urllib2.Request(url)
req.add_header('User-Agent',agent)
req.add_header('Host','blog.csdn.net')
req.add_header('Accept','*/*')
req.add_header('Referer','http://blog.csdn.net/mangoer_ys?viewmode=list')
req.add_header('GET',url)
html = urllib2.urlopen(req)
page = html.read().decode('gbk','ignore').encode('utf-8')

self.page = page
self.title = self.getTitle()
self.content = self.getContent()
self.saveFile()

def printInfo(self):
print('文章标题是：   '+self.title + '\n')
print('内容已经存储到out.txt文件中！')

def getTitle(self):
rex = re.compile('<title>(.*?)</title>',re.DOTALL)
match = rex.search(self.page)
if match:
return match.group(1)

return 'NO TITLE'

def getContent(self):
bs = BeautifulSoup(self.page)
html_content_list = bs.findAll('div',{'id':'article_content','class':'article_content'})
html_content = str(html_content_list[0])

rex_p = re.compile(r'(?:.*?)>(.*?)<(?:.*?)',re.DOTALL)
p_list = rex_p.findall(html_content)

content = ''
for p in p_list:
if p.isspace() or p == '':
continue
content = content + p
return content

def saveFile(self):

outfile = open('out.txt','a')
outfile.write(self.content)

def getNextArticle(self):
bs2 = BeautifulSoup(self.page)
html_nextArticle_list = bs2.findAll('li',{'class':'prev_article'})
# print str(html_nextArticle_list[0])
html_nextArticle = str(html_nextArticle_list[0])
# print html_nextArticle

rex_link = re.compile(r'<a href=\"(.*?)\"',re.DOTALL)
link = rex_link.search(html_nextArticle)
# print link.group(1)

if link:
next_url = 'http://blog.csdn.net' + link.group(1)
return next_url

return None

class Scheduler:
def __init__(self,url):
self.start_url = url

def start(self):
spider = CSDN_Blog_Spider(self.start_url)
spider.printInfo()

while True:
if spider.getNextArticle():
spider = CSDN_Blog_Spider(spider.getNextArticle())
spider.printInfo()
elif spider.getNextArticle() == None:
print 'All article haved been downloaded!'
break

time.sleep(10)

#url = input('请输入CSDN博文地址：')
url = "http://blog.csdn.net/mangoer_ys/article/details/38427979"

Scheduler(url).start()

程序中有个问题一直不能解决：不能使用标题去命名文件，所以所有的文章全部放在一个out.txt中，说的编码的问题，希望大神可以解决这个问题。