1)④爬取新浪军事新闻，并把内容存放到相应的文件夹中

__author__ = 'minmin'
#coding:utf-8
import re,urllib,sgmllib,os

#根据当前的url获取html
def getHtml(url):
    page = urllib.urlopen(url)
    html = page.read()
    page.close()
    return html

#根据html获取想要的文章内容
def func(str):
     result= re.findall(r"<p>([^<>]*)</p>",getHtml(url),re.M)
     artical =''
     for j in result:
         if len(j)<>0:
             j = j.replace("&nbsp;","")
             j = j.replace("<STRONG>","   ")#去掉<STRONG>,换成"     "
             j = j.replace("</STRONG>","   ")#去掉</STROGN>换成"     "
             artical = artical + j + '
'
     return  artical

#html链接的标签是“a”，链接的属性是“href”，也就是要获得html中所有tag=a，attrs=href 值。
class URLPaser(sgmllib.SGMLParser):
    def reset(self):
        sgmllib.SGMLParser.reset(self)
        self.urls = []

    def start_a(self,attrs):
        href = [v for k,v in attrs if k == 'href']
        if href:
            self.urls.extend(href)

IParser = URLPaser()
socket = urllib.urlopen("http://mil.news.sina.com.cn/")#打开这个网页

#fout = file('qq_art_urls.txt','w')#要把这个链接写到这个文件中
IParser.feed(socket.read())#分析啦

reg = 'http://mil.news.sina.com.cn/.*'#这个是用来匹配符合条件的链接，使用正则表达式匹配

pattern = re.compile(reg)


os.getcwd()#获得当前文件夹路径
os.path.sep#当前系统路径分隔符
 
#判断文件是否存在
if os.path.exists('sina_military')==False:
     os.makedirs('sina_military')
     
i = 0
url2 = []
for url in IParser.urls:#链接都存在urls里

    if pattern.match(url):
        if url not in url2:
            url2.append(url)
            artical = func(url)
            print artical
            if len(artical)<>0:
              i = i + 1
              f = open("sina_military/"+ str(i) + '.txt','a+')
              f.write(artical)
              f.close()