python多進程中使用pool，python進程pool

python多進程中使用pool，python進程pool

Python 多進程中使用pool，pool中指定每次運行幾個進程，當其中一個進程結束完畢後，會加入新的進程

 

#!/usr/bin/env python#coding: utf-8import multiprocessingimport os,time,randomdef Lee():    print "Run task Lee-%s" %(os.getpid()) #os.getpid()擷取當前的進程的ID    start=time.time()    time.sleep(random.random()*10) #random.random()隨機產生0-1之間的小數    end=time.time()    print 'Task Lee, runs %0.2f seconds.' %(end - start)def Marlon():    print "Run task Marlon-%s" %(os.getpid())    start=time.time()    time.sleep(random.random()*40)    end=time.time()    print 'Task Marlon runs %0.2f seconds.' %(end - start)def Allen():    print "Run task Allen-%s" %(os.getpid())    start=time.time()    time.sleep(random.random()*30)    end=time.time()    print 'Task Allen runs %0.2f seconds.' %(end - start)def Frank():    print "Run task Frank-%s" %(os.getpid())    start=time.time()    time.sleep(random.random()*20)    end=time.time()    print 'Task Frank runs %0.2f seconds.' %(end - start)        if __name__=='__main__':    function_list=  [Lee,Marlon,Allen,Frank]     print "parent process %s" %(os.getpid())    pool=multiprocessing.Pool(2)    for func in function_list:        pool.apply_async(func) #Pool執行函數，apply執行函數,當有一個進程執行完畢後，會添加一個新的進程到pool中    print 'Waiting for all subprocesses done...'    pool.close()    pool.join() #調用join之前，一定要先調用close() 函數，否則會出錯, close()執行後不會有新的進程加入到pool,join函數等待素有子進程結束    print 'All subprocesses done.'