如何在进程池中使用共享/托管字典(Python 3.x)

我正在做一个项目,需要我从一些文件中提取大量信息。关于这个项目的格式和大部分信息与我要问的问题无关。我不知道如何将此字典与进程池中的所有进程共享。

这是我的代码(更改了变量名,删除了大部分代码,只需要知道部分):

import json

import multiprocessing
from multiprocessing import Pool, Lock, Manager

import glob
import os

def record(thing, map):

    with mutex:
        if(thing in map):
            map[thing] += 1
        else:
            map[thing] = 1


def getThing(file, n, map): 
    #do stuff
     thing = file.read()
     record(thing, map)


def init(l):
    global mutex
    mutex = l

def main():

    #create a manager to manage shared dictionaries
    manager = Manager()

    #get the list of filenames to be analyzed
    fileSet1=glob.glob("filesSet1/*")
    fileSet2=glob.glob("fileSet2/*")

    #create a global mutex for the processes to share
    l = Lock()   

    map = manager.dict()
    #create a process pool, give it the global mutex, and max cpu count-1 (manager is its own process)
    with Pool(processes=multiprocessing.cpu_count()-1, initializer=init, initargs=(l,)) as pool:
        pool.map(lambda file: getThing(file, 2, map), fileSet1) #This line is what i need help with

main()

据我所知,lamda函数应该可以工作。我需要帮助的行是:pool.map(lambda file:getThing(file,2,map),fileSet1)。这给了我一个错误。给出的错误是“AttributeError:Cant pickle local object'main..'”。

任何帮助都将不胜感激!