【Python】使用 multiprocessing.dummy 执行多线程任务

1. # -*- coding: utf-8 -*-  
2. # from multiprocessing import Pool 多进程  
3. from multiprocessing.dummy import Pool as ThreadPool #多线程  
4. import time  
5. import urllib2  
6.   
7. urls = [  
8. 'http://www.python.org',   
9. 'http://www.python.org/about/',  
10. 'http://www.onlamp.com/pub/a/python/2003/04/17/metaclasses.html',  
11. 'http://www.python.org/doc/',  
12. 'http://www.python.org/download/',  
13. 'http://www.python.org/getit/',  
14. 'http://www.python.org/community/',  
15. 'https://wiki.python.org/moin/',  
16. 'http://planet.python.org/',  
17. 'https://wiki.python.org/moin/LocalUserGroups',  
18. 'http://www.python.org/psf/',  
19. 'http://docs.python.org/devguide/',  
20. 'http://www.python.org/community/awards/'  
21.     ]  
22.   
23. # 单线程  
24. start = time.time()  
25. results = map(urllib2.urlopen, urls)  
26. print 'Normal:', time.time() - start  
27.   
28. # 多线程  
29. start2 = time.time()  
30. # 开4个 worker，没有参数时默认是 cpu 的核心数  
31. pool = ThreadPool(4)  
32. # 在线程中执行 urllib2.urlopen(url) 并返回执行结果  
33. results2 = pool.map(urllib2.urlopen, urls)  
34. pool.close()  
35. pool.join()  
36. print 'Thread Pool:', time.time() - start2