多进程全局变量失效、变量共享问题

*多进程因为不共享空间，函数内部append，±等处理函数外部变量会不起作用

参考：https://www.bilibili.com/video/BV1EZ4y1X7Aj
https://www.bilibili.com/video/BV1p64y1i7KA

1、共享可以通过间接return返回值保存pp，迭代再处理

#多进程
from multiprocessing import Pool

def foo(x):
    return x*x

if __name__=="__main__":
    p = Pool(processes=5)

    pp = p.imap(foo,range(10))
    print(pp)
    kk=[]
    for ii in tqdm(pp):
        kk.append(ii)
    print(kk)

2、可以用共享内存Manager

from multiprocessing import Pool,Value,Manager,Lock
# import time
#
from tqdm import tqdm
#
#
def test(i,lists,lock):
    with lock:
        print(i)
        lists.append(i**3)



if __name__=="__main__":
    print(111)

    with Manager() as manager:
        share_list = manager.list()
        lock = manager.Lock()

        pool = Pool(processes=2)
        for i in tqdm(range(100)):
            pool.apply(test,args=(i,share_list,lock))

        print(share_list)