Python 简易抓取界面

鸬鹚洲

初学Python,参考相关资料做了个简易抓取网页界面，主要为了增加对python的熟识度。主要是通过urllib2获取预先指定的地址的页面，通过BeautifulSoup来解析界面元素，找到href标签，并将相关的数据存入数据库，以方便后面取出继续抓取。整个抓取和解析也是基于多线程与队列来控制的。做的比较简单与粗糙，后续深入可以改进。


import DBHelper
import CodeHelper
import urllib2
from bs4 import BeautifulSoup
import threading as thread
import Queue
import time
class Resource:
def __init__(self, url, text, content, status):
self._url = url
self._text = text
self._content = content
self._status = status
def insert(self):
dbHelper = DBHelper.DBHelper()
sql = 'select * from resource where url=%s'
data = dbHelper.read(sql, [self._url])
if data is not None :
return
sql = 'insert into resource(url,text,content,status) values(%s,%s,%s,%s)'
print 'url: %s content: %s status: %s' %(self._url, self._text, self._content, self._status)
dbHelper.execute(sql, [self._url, self._text, self._content, self._status]);
dbHelper.commint()
dbHelper.close()
def updateStatus(self):
dbHelper = DBHelper.DBHelper()
sql = 'update resource set status=%s where url=%s'
dbHelper.execute(sql, [self._status, self._url]);
dbHelper.commint()
dbHelper.close()
def updateContentAndStatus(self):
dbHelper = DBHelper.DBHelper()
sql = 'update resource set content=%s,status=%s where url=%s'
dbHelper.execute(sql, [self._content, self._status, self._url]);
dbHelper.commint()
dbHelper.close()
def readListByStatus(self):
dbHelper = DBHelper.DBHelper()
sql = 'select * from resource where status=%s'
return dbHelper.readList(sql, [self._status]);
def readList(self):
dbHelper = DBHelper.DBHelper()
return dbHelper.readList('select * from resource');
class ResourceThread(thread.Thread):
def __init__(self, task_queue):
thread.Thread.__init__(self)
self._task_queue = task_queue
self.setDaemon(True)
self.start()
def run(self):
print 'current thread name %s' %thread.currentThread().name
while True :
try :
func, args = self._task_queue.get(block = False)
func(args)
self._task_queue.task_done()
except Exception,e :
print str(e)
break
class ResourceManager:
def __init__(self, taskNum = 10, threadNum = 2) :
self._task_queue = Queue.Queue()
self._threads = []
self.__init__task_queue__(taskNum)
self.__init__thread_pool(threadNum)
def __init__task_queue__(self, taskNum) :
for i in range(taskNum) :
print 'this is %s task' %i
self.add_task(do_task, i)
def __init__thread_pool(self, threadNum) :
for i in range(threadNum) :
print 'threadNum %s' %i
resourceThread = ResourceThread(self._task_queue)
self._threads.append(resourceThread)
def add_task(self, func, *args) :
self._task_queue.put((func, args))
def check_queue(self):
return self._task_queue.qsize()
def wait_for_complete(self) :
for thread_item in self._threads :
if thread_item.isAlive() :
thread_item.join()
def do_task(args):
print 'this task args %s' %args
resource = Resource(None, None, None, 0)
data = resource.readListByStatus()
print 'read status 0 data is %s' %data
if data is None :
return
for item in data :
url = item[1]
if url is None or url.find('http://') == -1 :
continue
content = urllib2.urlopen(url).read()
html = BeautifulSoup(content)
fetch_resource = Resource(url, None, str(html.find('body'))[0:9999], 1)
fetch_resource.updateContentAndStatus()
aLinks = html.find_all('a')
print 'aLinks %s' %aLinks
for aLink in aLinks :
href = aLink.get('href')
a_text = CodeHelper.encodeContent(aLink.get_text())
print 'href %s text %s' %(href, a_text)
subResource = Resource(href, a_text, '', 0)
subResource.insert()
def execute():
urls = ['http://www.kuwo.cn', 'http://www.1ting.com/', 'http://www.kugou.com/', 'http://y.qq.com/']
for url in urls :
resource = Resource(url, None, 0)
resource.insert()
start = time.time()
resource_manager =  ResourceManager(20, 4)
resource_manager.wait_for_complete()
end = time.time()
print "cost all time: %s" % (end-start)
if __name__ == '__main__':
execute()