Python

Question

我想知道是否可以将参数传递到线程池函数中？

from multiprocessing.dummy import Pool as ThreadPool 

def mainFunc():
    myArray = ["A", "B", "C"]

    pool = ThreadPool(8) 
    pool.map(threadFunc, myArray)   # how is it possible to give >>threadFunc<< another argument >>text1<<
    pool.close()
    pool.join()

def threadFunc(text2):
    text1 = "Hello "                # this should be given as a argument  of the function
    print text1 + text2

mainFunc()

这是我想做的事情的一个简单示例。我如何将 text1 作为 threadFunc 函数的第二个参数？

已解决：

我用一个简单的全局可访问变量解决了这个问题……但这只是我现在遇到的问题的一个解决方案……使用 multiprocessing.Process 是一个更好的主意…… .

import sys
from multiprocessing.dummy import Pool as ThreadPool 

this = sys.modules[__name__] 

def mainFunc():
    myArray = ["A", "B", "C"]
    this.text1 = "Hello "

    pool = ThreadPool(8) 
    pool.map(threadFunc, myArray)   # how is it possible to give >>threadFunc<< another argument >>text1<<
    pool.close()
    pool.join()

def threadFunc(text2):
    print this.text1 + text2

mainFunc()

Answer 1

官方 python 文档说

A parallel equivalent of the map() built-in function (it supports only one iterable argument though). It blocks until the result is ready.

因此无法添加另一个参数，但您始终可以将 text1 添加为 myArray 的最后一个元素，并在使用后将其弹出。

您还可以使用multiprocessing.Process而不是游泳池。在这种情况下，您可以轻松添加另一个参数。

def f(name):
    print 'hello', name

if __name__ == '__main__':
    p = Process(target=f, args=('bob',))
    p.start()
    p.join()

Answer 2

您可以在元组或列表中传递任意数量的参数：

from multiprocessing.dummy import Pool as ThreadPool 

def mainFunc():
    myArray = ["A", "B", "C"]
    text1 = "Hello "

    pool = ThreadPool(8)

    # combine text1 with each element in myArray
    args_generator = ((text1, x) for x in myArray)

    pool.map(threadFunc, args_generator)
    pool.close()
    pool.join()

def threadFunc(args):
    # unpack arguments
    text1, text2 = args
    print text1 + text2

Python - 多处理池 Class：线程函数可以包含参数吗？

Python - Multiprocessing Pool Class: Can the Thread Function contain arguments?

multithreading

multiprocessing

pool