Return value from thread

I suggest you instantiate a Queue.Queue before starting the thread, and pass it as one of the thread's args: before the thread finishes, it .puts the result on the queue it received as an argument. The parent can .get or .get_nowait it at will.

Queues are generally the best way to arrange thread synchronization and communication in Python: they're intrinsically thread-safe, message-passing vehicles -- the best way to organize multitasking in general!-)

You should pass a Queue instance as a parameter then you should .put() your return object into the queue. You can gather the return value via queue.get() whatever object you put.

Sample:

queue = Queue.Queue()thread_ = threading.Thread(                target=target_method,                name="Thread1",                args=[params, queue],                )thread_.start()thread_.join()queue.get()def target_method(self, params, queue): """ Some operations right here """ your_return = "Whatever your object is" queue.put(your_return)

Use for multiple threads:

#Start all threads in thread pool    for thread in pool:        thread.start()        response = queue.get()        thread_results.append(response)#Kill all threads    for thread in pool:        thread.join()

I use this implementation and it works great for me. I wish you do so.

Use lambda to wrap your target thread function and pass its return value back to the parent thread using a queue. (Your original target function remains unchanged without extra queue parameter.)

Sample code:

import threadingimport queuedef dosomething(param):    return param * 2que = queue.Queue()thr = threading.Thread(target = lambda q, arg : q.put(dosomething(arg)), args = (que, 2))thr.start()thr.join()while not que.empty():    print(que.get())

Output:

4