Multiprocessing in Python with tuple and storng result in a list of variables-CodePudding

I have a list of functions that I want to execute parallely

list1 = [a,b,c]

List b contains a mapping of arguments to be passed to each function respectively. i,e

list2 = [d,e,f]

So function a takes argument d, function b takes argument e and so on.

I am creating a tuple of function and args using below

tasks = list(zip(list1,list2))

running the parallel function call below

futures = [pool.apply_async(*t) for t in tasks]

Now I have another list c containing variables to store the result for each of the function.

list3 = [g,h,i]

Therefore result of function a taking argument d should be stored in list3[0], result of function b taking argument e should be stored in list3[1] and so on. How can I achieve this ?

CodePudding user response：

Well, your futures are in that order already, so

list3 = [fut.get() for fut in futures]

will wait for them to be ready, and store the results in that list:

import multiprocessing


def fun1(arg):
    return f"fun1! {arg}???"


def fun2(arg):
    return f"fun2? {arg}!"


def fun3(arg):
    return f"fun3: {arg}..."


def main():
    funcs = [fun1, fun2, fun3]
    argses = [("hey",), ("ho",), ("let's go",)]
    with multiprocessing.Pool() as pool:
        futures = [pool.apply_async(*t) for t in zip(funcs, argses)]
        results = [f.get() for f in futures]
    print(results)


if __name__ == '__main__':
    main()

prints out

['fun1! hey???', 'fun2? ho!', "fun3: let's go..."]