Many scenes in order not to block , Need asynchronous callback mechanism . This is a simple example .
#!/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
Asynchronous task queue
_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():
"""
Asynchronous task queue consumers
"""
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> 
