Python threading with PyQt as decorator

Question

Hello fellow Overflowers, here's another code I've stuck in. I am using decorator to run some functions asycronously.

file: async.py

from threading import Thread
from functools import wraps


def run(func):
    @wraps(func)
    def async_func(*args, **kwargs):
        func_hl = Thread(target=func, args=args, kwargs=kwargs)
        func_hl.daemon = False
        func_hl.start()
        return func_hl

    return async_func

And then:

import async

[...]

@async.run
def foo():
   while condition:
       do_something()

But now I make a project with QT and those QThreads.

So,the question is: how should I improve my decorator to be QT-friendly? My effort so far was like that:

def better_thread(to_wrap):
    class MyThread(QtCore.QThread):
        def run(self, *args, **kwargs):
            _res = to_wrap(*args, **kwargs)
            return _res

    @wraps(to_wrap)
    def async_func(*args, **kwargs):
        def finish():
            pass
        mythread = MyThread()
        mythread.start()
        result = mythread.run(*args, **kwargs)
        return result
    return async_func

Which I beleive is ugly and wrong. Could you help me?

Python threads works perfectly with Qt, did you really need this? — Ceppo93, Sep 04 '16 at 18:50
@Ceppo93 Some of those threads are working with gui, thus making qt threads preferrable way for seamless experience. — Pavel M., Sep 08 '16 at 07:01

score 2 · Accepted Answer · edited May 23 '17 at 12:32

First here: Threading in a PyQt application: Use Qt threads or Python threads?, for some usufull advise.

A simple "refactoring" of your code, to make it cleaner:

class Runner(QtCore.QThread):

    def __init__(self, target, *args, **kwargs):
        super().__init__()
        self._target = target
        self._args = args
        self._kwargs = kwargs

    def run(self):
        self._target(*self._args, **self._kwargs)

def run(func):
    @wraps(func)
    def async_func(*args, **kwargs):
        runner = Runner(func, *args, **kwargs)
        # Keep the runner somewhere or it will be destroyed
        func.__runner = runner
        runner.start()

    return async_func

EDIT

A simple test:

@run
def test():
    sleep(1)
    print('TEST')


test()
sleep(2)
print('END')

Ceppo93, you might call it placebo, but I really feel my app is working now more seamlessly with Qthread. Also big thanks for the tip to keep the runner, that was very useful! — Pavel M., Sep 09 '16 at 21:52

Python threading with PyQt as decorator

1 Answers1