Python多重处理：AttributeError：'Test'对象没有属性'get_type'

简短的简短版本：

我在并行化使用实例方法的代码时遇到问题。

更长的版本：

此 python 代码产生错误：

Error
Traceback (most recent call last):
  File "/Users/gilzellner/dev/git/3.2.1-build/cloudify-system-tests/cosmo_tester/test_suites/stress_test_openstack/test_file.py", line 24, in test
self.pool.map(self.f, [self, url])
File "/Users/gilzellner/.virtualenvs/3.2.1-build/lib/python2.7/site-packages/pathos/multiprocessing.py", line 131, in map
return _pool.map(star(f), zip(*args)) # chunksize
File "/Users/gilzellner/.virtualenvs/3.2.1-build/lib/python2.7/site-packages/multiprocess/pool.py", line 251, in map
return self.map_async(func, iterable, chunksize).get()
File "/Users/gilzellner/.virtualenvs/3.2.1-build/lib/python2.7/site-packages/multiprocess/pool.py", line 567, in get
raise self._value
AttributeError: 'Test' object has no attribute 'get_type'

这是我遇到的实际问题的简化版本。

import urllib2
from time import sleep
from os import getpid
import unittest
from pathos.multiprocessing import ProcessingPool as Pool

class Test(unittest.TestCase):

    def f(self, x):
        print urllib2.urlopen(x).read()
        print getpid()
        return

    def g(self, y, z):
        print y
        print z
        return

    def test(self):
        url = "http://nba.com"
        self.pool = Pool(processes=1)
        for x in range(0, 3):
            self.pool.map(self.f, [self, url])
            self.pool.map(self.g, [self, url, 1])
        sleep(10)

由于此处的建议，我正在使用 pathos.multiprocessing：多重处理：池和 pickle 错误 - Pickling 错误：无法 pickle ：属性查找 __builtin__.instancemethod 失败 https://stackoverflow.com/questions/12396451/multiprocessing-pool-and-pickle-error-pickling-error-cant-pickle-type-in

在使用pathos.multiprocessing之前，错误是：

"PicklingError: Can't pickle <type 'instancemethod'>: attribute lookup __builtin__.instancemethod failed"

您正在使用多处理map方法不正确。
根据蟒蛇文档 https://docs.python.org/2/library/multiprocessing.html#multiprocessing.pool.multiprocessing.Pool.map:

map() 内置函数的并行等效项（它仅支持 不过有一个可迭代的参数）。

哪里标准map:

将函数应用于可迭代的每个项目并返回一个列表 结果。

用法示例 https://docs.python.org/2/library/multiprocessing.html#introduction:

from multiprocessing import Pool

def f(x):
    return x*x

if __name__ == '__main__':
    p = Pool(5)
    print(p.map(f, [1, 2, 3]))

您正在寻找的是应用异步 https://docs.python.org/2/library/multiprocessing.html#multiprocessing.pool.multiprocessing.Pool.apply_async method:

def test(self):
    url = "http://nba.com"
    self.pool = Pool(processes=1)
    for x in range(0, 3):
        self.pool.apply_async(self.f, args=(self, url))
        self.pool.apply_async(self.g, args=(self, url, 1))
    sleep(10)