python做出新闻聚合项目

2020-11-27 来源：好走旅游网

这次给大家带来python做出新闻聚合项目，python做出新闻聚合项目的注意事项有哪些，下面就是实战案例，一起来看一下。

先上代码，然后再来逐一分析：

from nntplib import NNTP
from time import strftime,time,localtime
from email import message_from_string
from urllib import urlopen
import textwrap
import re
day = 24*60*60
def wrap(string,max=70):
 '''
 '''
 return '
'.join(textwrap.wrap(string)) + '
'
class NewsAgent:
 '''
 '''
 def init(self):
 self.sources = []
 self.destinations = []
 def addSource(self,source):
 self.sources.append(source)
 def addDestination(self,dest):
 self.destinations.append(dest)
 def distribute(self):
 items = []
 for source in self.sources:
 items.extend(source.getItems())
 for dest in self.destinations:
 dest.receiveItems(items)
class NewsItem:
 def init(self,title,body):
 self.title = title
 self.body = body
class NNTPSource:
 def init(self,servername,group,window):
 self.servername = servername
 self.group = group
 self.window = window
 def getItems(self):
 start = localtime(time() - self.window*day)
 date = strftime('%y%m%d',start)
 hour = strftime('%H%M%S',start)
 server = NNTP(self.servername)
 ids = server.newnews(self.group,date,hour)[1]
 for id in ids:
 lines = server.article(id)[3]
 message = message_from_string('
'.join(lines))
 title = message['subject']
 body = message.get_payload()
 if message.is_multipart():
 body = body[0]
 yield NewsItem(title,body)
 server.quit()
class SimpleWebSource:
 def init(self,url,titlePattern,bodyPattern):
 self.url = url
 self.titlePattern = re.compile(titlePattern)
 self.bodyPattern = re.compile(bodyPattern)
 def getItems(self):
 text = urlopen(self.url).read()
 titles = self.titlePattern.findall(text)
 bodies = self.bodyPattern.findall(text)
 for title.body in zip(titles,bodies):
 yield NewsItem(title,wrap(body))
class PlainDestination:
 def receiveItems(self,items):
 for item in items:
 print item.title
 print '-'*len(item.title)
 print item.body
class HTMLDestination:
 def init(self,filename):
 self.filename = filename
 def receiveItems(self,items):
 out = open(self.filename,'w')
 print >> out,'''
 <html>
 <head>
 <title>Today's News</title>
 </head>
 <body>
 <h1>Today's News</hi>
 '''
 print >> out, '<ul>'
 id = 0
 for item in items:
 id += 1
 print >> out, '<li><a href="#" rel="external nofollow" >%s</a></li>' % (id,item.title)
 print >> out, '</ul>'
 id = 0
 for item in items:
 id += 1
 print >> out, '<h2><a name="%i">%s</a></h2>' % (id,item.title)
 print >> out, '<pre>%s</pre>' % item.body
 print >> out, '''
 </body>
 </html>
 '''
def runDefaultSetup():
 agent = NewsAgent()
 bbc_url = 'http://news.bbc.co.uk/text_only.stm'
 bbc_title = r'(?s)a href="[^" rel="external nofollow" ]*">s*<b>s*(.*?)s*</b>'
 bbc_body = r'(?s)</a>s*<br/>s*(.*?)s*<'
 bbc = SimpleWebSource(bbc_url, bbc_title, bbc_body)
 agent.addSource(bbc)
 clpa_server = 'news2.neva.ru'
 clpa_group = 'alt.sex.telephone'
 clpa_window = 1
 clpa = NNTPSource(clpa_server,clpa_group,clpa_window)
 agent.addSource(clpa)
 agent.addDestination(PlainDestination())
 agent.addDestination(HTMLDestination('news.html'))
 agent.distribute()
if name == 'main':
 runDefaultSetup()

这个程序，首先从整体上进行分析，重点部分在于NewsAgent，它的作用是存储新闻来源，存储目标地址，然后在分别调用来源服务器（NNTPSource以及SimpleWebSource）以及写新闻的类（PlainDestination和HTMLDestination）。所以从这里也看的出，NNTPSource是专门用来获取新闻服务器上的信息的，SimpleWebSource是获取一个url上的数据的。而PlainDestination和HTMLDestination的作用很明显，前者是用来输出获取到的内容到终端的，后者是写数据到html文件中的。

有了这些分析，然后在来看主程序中的内容，主程序就是来给NewsAgent添加信息源和输出目的地址的。

这确实是个简单的程序，不过这个程序可是用到了分层了。

相信看了本文案例你已经掌握了方法，更多精彩请关注Gxl网其它相关文章！

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python做出新闻聚合项目