tkinter MP working like a charm

[Wu Xi]

from tkinter import *                                    #    I cant see anything wrong with this , it works like a charm
from tkinter import messagebox                           #    is there a serious concern doing things his way ? 
import asyncio , threading ,  random                     #    goal is multi tasking with the GUI not freezing before loop completed
 							 #    which is being achieved here !  
def _asyncio_thread(async_loop):
    async_loop.run_until_complete(do_urls())

def do_work(async_loop):
    """ Button-Event-Handler starting stuff """
    threading.Thread(target=_asyncio_thread, args=(async_loop,)).start()

async def one_url(url):
    """ One task. """
    sec = random.randint(1, 8)
    await asyncio.sleep(sec  )
    return 'url: {}  ---  sec: {}'.format(url, sec)

async def do_urls():
    """ Creating and starting 10 tasks.         """
    tasks   = [one_url(url)  for url  in range(10)]
    completed, pending =  await asyncio.wait(tasks)
    results = [task.result() for task in completed]
    print('\n'.join(results))


def do_nofreeze():
    messagebox.showinfo(message='see, Tkinter is still responsive')

def submain(async_loop):
    root = Tk()
    b1 = Button(master=root, text='do work',       command= lambda:do_work( async_loop)).pack()
    b2 = Button(master=root, text='Frozen?',       command=do_nofreeze                 ).pack()
    root.mainloop()


if __name__ == '__main__':
    async_loop = asyncio.get_event_loop()    #  all in this loop
    submain(async_loop)