无法更新多重处理的manager.dict()中的嵌套字典值 [英] Unable to update nested dictionary value in multiprocessing's manager.dict()

问题描述

我正在尝试更新多处理模块的manager.dict()的嵌套字典中的键，但无法这样做.它不会更新值，也不会引发任何错误.

I am trying to update a key in a nested dictionary of multiprocessing module's manager.dict() but not able to do so. It doesn't update the value and doesn't throw any error too.

代码:

import time
import random
from multiprocessing import Pool, Manager

def spammer_task(d, token, repeat):
    success = 0
    fail = 0
    while success+fail<repeat:
        time.sleep(random.random()*2.0)
        if (random.random()*100)>98.0:
            fail+=1
        else:
            success+=1
        d[token] = {
            'status': 'ongoing',
            'fail': fail,
            'success': success,
            'repeat': repeat
        }
    print d[token]['status']
    d[token]['status'] = 'complete'
    return

p = Pool()
m = Manager()
d = m.dict()

p.apply_async(spammer_task (d, 'abc', 5))
print d

输出:

进行中

{'abc':{'状态':'进行中'，'失败':0，'重复':5，'成功':5}}

{'abc': {'status': 'ongoing', 'fail': 0, 'repeat': 5, 'success': 5}}

我的期望是，当while循环结束时，它应该使d ['abc'] ['status'] =完成.但是在最终打印中，它仅将状态打印为进行中".

My expectations are that as soon as while loop ends, it should make d['abc']['status'] = complete. But on final print it prints its status as 'ongoing' only.

推荐答案

不知道为什么，但是Manager DictProxy对象似乎无法处理嵌套部分的变异.该代码有效:

not sure why, but the Manager DictProxy object cant seems to handle mutating a nested part. this code works:

import time
import random
from multiprocessing import Pool, Manager

def spammer_task(d, token, repeat):
    success = 0
    fail = 0
    while success+fail<repeat:
        time.sleep(random.random()*2.0)
        if (random.random()*100)>98.0:
            fail+=1
        else:
            success+=1
        d[token] = {
            'status': 'ongoing',
            'fail': fail,
            'success': success,
            'repeat': repeat,
        }
    print d[token]['status']
    foo = d[token]
    foo['status'] = 'complete'
    d[token] = foo
    return

p = Pool()
m = Manager()
d = m.dict()

p.apply_async(spammer_task(d, 'abc', 5))
print d

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