python 並行處理數據

來源：https://blog.csdn.net/weixin_42001089/article/details/88843152

import multiprocessing
import time
import os
print("溫馨提示：本機為",os.cpu_count(),"核CPU")  
 
def func(msg):
    print "msg:", msg
    time.sleep(3)
    print "end"
 
if __name__ == "__main__":
    #這里開啟了4個進程
    pool = multiprocessing.Pool(processes = 4)
    for i in xrange(4):
        msg = "hello %d" %(i)
        pool.apply_async(func, (msg, ))   
 
    pool.close()
    pool.join()   #調用join之前，先調用close函數，否則會出錯。執行完close后不會有新的進程加入到pool,join函數等待所有子進程結束
    print "Successfully"