Python的并发并行[4] -> 并发[0] -> 利用线程池启动线程

利用线程池启动线程

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submit与map启动线程

利用两种方式分别启动线程，同时利用with上下文管理来对线程池进行控制

 from concurrent.futures import ThreadPoolExecutor as tpe
 from concurrent.futures import ProcessPoolExecutor as ppe
 from time import ctime, sleep
 from random import randint

 def foo(x, name):
     print('%s%d starting at' % (name, x), ctime())
     sleep(randint(1, 7))
     print('%s%d completed at' % (name, x), ctime())

 # Use submit function
 print('-----Using submit function-----')
 #executor = tpe(7)
 #with executor:
 with tpe(7) as executor:
     for i in range(5):
         executor.submit(foo, i, 'No.')

 # Use map function
 print('-----Using map function-----')
 with tpe(7) as executor:
     executor.map(foo, range(5), ['No_a.', 'No_b.', 'No_c.', 'No_d.', 'No_e.'])

 # TODO: Learn more about ProcessPoolExecutor
 """
 with ppe(2) as executor:
     executor.submit(foo, 1, 'No.')
 """

定义foo方法，并运用两种方式启动线程池执行器，其中with tpe(7) as executor语句等价于executor = tpe(), with executor，with的上下文管理可以保证执行器在所有submit的foo函数完成之前挂起等待。

运行得到结果

-----Using submit function-----
No.0 starting at Wed Aug  2 14:33:06 2017
No.1 starting at Wed Aug  2 14:33:06 2017
No.2 starting at Wed Aug  2 14:33:06 2017
No.3 starting at Wed Aug  2 14:33:06 2017
No.4 starting at Wed Aug  2 14:33:06 2017
No.2 completed at Wed Aug  2 14:33:07 2017
No.0 completed at Wed Aug  2 14:33:08 2017
No.3 completed at Wed Aug  2 14:33:08 2017
No.1 completed at Wed Aug  2 14:33:09 2017
No.4 completed at Wed Aug  2 14:33:13 2017
-----Using map function-----
No_a.0 starting at Wed Aug  2 14:33:13 2017
No_b.1 starting at Wed Aug  2 14:33:13 2017
No_c.2 starting at Wed Aug  2 14:33:13 2017
No_d.3 starting at Wed Aug  2 14:33:13 2017
No_e.4 starting at Wed Aug  2 14:33:13 2017
No_b.1 completed at Wed Aug  2 14:33:14 2017
No_c.2 completed at Wed Aug  2 14:33:14 2017
No_d.3 completed at Wed Aug  2 14:33:14 2017
No_a.0 completed at Wed Aug  2 14:33:18 2017
No_e.4 completed at Wed Aug  2 14:33:18 2017  

查看结果可以看出，两者效果相近。

未完待续...

相关阅读

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1. concurrent.future 模块