进程池与线程池（concurrent.futures）

 1 from concurrent.futures import ProcessPoolExecutor
 2 import os,time,random
 3 def task(n):
 4     print('%s is running'%os.getpid())
 5     time.sleep(random.randint(1,2))
 6     return n**2
 7 if __name__ == '__main__':
 8     p = ProcessPoolExecutor()     #默认开启四个进程池
 9     l = []
10     start = time.time()
11     for i in range(10):
12         obj = p.submit(task,i)
13         l.append(obj)
14     p.shutdown()
15     print('='*30)
16     print([obj for obj in l])
17     print(time.time() - start)

进程池