Why can I pass an instance method to multiprocessing.Process, but not a multiprocessing.Pool?

Question

I am trying to write an application that applies a function concurrently with a multiprocessing.Pool. I would like this function to be an instance method (so I

Answer 1

Here is a easier way work in Python 2, just wrap the original instance method. Works well on macOS and Linux, not work on Windows, tested Python 2.7

from multiprocessing import Pool

class Person(object):
    def __init__(self):
        self.name = 'Weizhong Tu'

    def calc(self, x):
        print self.name
        return x ** 5


def func(x, p=Person()):
    return p.calc(x)


pool = Pool()
print pool.map(func, range(10))