很多場景為了不阻塞，都需要異步回調機制。這是一個簡單的例子。

#!/usr/bin/env python

-- coding: UTF-8 --
import logging
import queue
import threading
def func_a(a, b):
    return a + b
def func_b():
    pass
def func_c(a, b, c):
    return a, b, c
異步任務隊列
_task_queue = queue.Queue()
def async_call(function, callback, *args, **kwargs):
    _task_queue.put({
        'function': function,
        'callback': callback,
        'args': args,
        'kwargs': kwargs
    })
def _task_queue_consumer():
    """
    異步任務隊列消費者
    """
    while True:
        try:
            task = _task_queue.get()
            function = task.get('function')
            callback = task.get('callback')
            args = task.get('args')
            kwargs = task.get('kwargs')
            try:
                if callback:
                    callback(function(*args, **kwargs))
            except Exception as ex:
                if callback:
                    callback(ex)
            finally:
                _task_queue.task_done()
        except Exception as ex:
            logging.warning(ex)
def handle_result(result):
    print(type(result), result)
if name == 'main':
    t = threading.Thread(target=_task_queue_consumer)
    t.daemon = True
    t.start()

async_call(func_a, handle_result, 1, 2)
async_call(func_b, handle_result)
async_call(func_c, handle_result, 1, 2, 3)
async_call(func_c, handle_result, 1, 2, 3, 4)

_task_queue.join()</pre>