发布于 2014-08-10 14:27:35 | 256 次阅读 | 评论: 0 | 来源: 网友投递
这里有新鲜出炉的Python3 官方中文指南，程序狗速度看过来！
Python编程语言
Python 是一种面向对象、解释型计算机程序设计语言，由Guido van Rossum于1989年底发明，第一个公开发行版发行于1991年。Python语法简洁而清晰，具有丰富和强大的类库。它常被昵称为胶水语言，它能够把用其他语言制作的各种模块（尤其是C/C++）很轻松地联结在一起。
本文是一个利用python写的多线程抓取天涯帖子内容的示例代码,使用python的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,感兴趣的同学参考下.
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 = ['rnrnrnrn'.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>', 'rn').replace('<br />', 'rn').replace(' ', '')
tx_file.write(tx.strip()+'rn'*4)
tx_file.close()
def main():
url = 'http://bbs.tianya.cn/post-16-996521-1.shtml'
file_name ='abc.txt'
my_page = page(url)
my_dict = {}
print 'page num is : %s' % my_page
threads = []
"""根据页数构造urls进行多线程下载"""
for num in range(1, my_page+1):
myurl = '%s%s.shtml' % (url[:-7], num)
downlist = Down_Tianya(myurl, num, my_dict)
downlist.start()
threads.append(downlist)
"""检查下载完成后再进行写入"""
for t in threads:
t.join()
write_text(my_dict, file_name)
print 'All download finished. Save file at directory: %s' % os.getcwd()
if __name__ == '__main__':
main()
down_tianya.py
import urllib
import re
import threading
import os
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('<div class="atl-item".*?<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 = ['rnrnrnrn'.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>', 'rn').replace('<br />', 'rn').replace(' ', '')
tx_file.write(tx.strip()+'rn'*4)
tx_file.close()
def main():
url = 'http://bbs.tianya.cn/post-16-996521-1.shtml'
file_name ='abc.txt'
my_page = page(url)
my_dict = {}
print 'page num is : %s' % my_page
threads = []
"""根据页数构造urls进行多线程下载"""
for num in range(1, my_page+1):
myurl = '%s%s.shtml' % (url[:-7], num)
downlist = Down_Tianya(myurl, num, my_dict)
downlist.start()
threads.append(downlist)
"""检查下载完成后再进行写入"""
for t in threads:
t.join()
write_text(my_dict, file_name)
print 'All download finished. Save file at directory: %s' % os.getcwd()
if __name__ == '__main__':
main()