python多线程抓取天涯帖子内容示例

使用re, urllib, threading　多线程抓取天涯帖子内容，设置url为需抓取的天涯帖子的第一页，设置file_name为下载后的文件名

代码如下:
#coding:utf-8

import urllib
import re
import threading
import os, time

class Down_Tianya(threading.Thread):
    """多线程下载"""
    def __init__(self, url, num, dt):
        threading.Thread.__init__(self)
        self.url = url
        self.num = num
        self.txt_dict = dt

    def run(self):
        print 'downling from %s' % self.url
        self.down_text()

    def down_text(self):
        """根据传入的url抓出各页内容，按页数做键存入字典"""
        html_content =urllib.urlopen(self.url).read()
        text_pattern = re.compile('<span>时间：(.*?)</span>.*?<!-- <div class="host-ico">楼主</div> -->.*?<div class="bbs-content.*?>/s*(.*?)</div>', re.DOTALL)
        text = text_pattern.findall(html_content)
        text_join = ['/r/n/r/n/r/n/r/n'.join(item) for item in text]
        self.txt_dict[self.num] = text_join

def page(url):
    """根据第一页地址抓取总页数"""
    html_page = urllib.urlopen(url).read()
    page_pattern = re.compile(r'<a href="/S*?">(/d*)</a>/s*<a href="/S*?" class="/S*?">下页</a>')
    page_result = page_pattern.search(html_page)
    if page_result:
        page_num = int(page_result.group(1))
        return page_num

def write_text(dict, fn):
    """把字典内容按键（页数）写入文本，每个键值为每页内容的list列表"""
    tx_file = open(fn, 'w+')
    pn = len(dict)
    for i in range(1, pn+1):
        tx_list = dict[i]
        for tx in tx_list:
            tx = tx.replace('<br>', '/r/n').replace('<br />', '/r/n').replace(' ', '')
            tx_file.write(tx.strip()+'/r/n'*4)
    tx_file.close()

def main():
    url = 'http://bbs.tianya.cn/post-16-996521-1.shtml'
    file_name ='abc.txt'