title: Calling async function from button command Tkinter
body: <p>I want to call an async function from a Tkinter button command, or rather want to let the function run asynchronously, so that the tkinter window is responsive. <br>I've tried <code>command = open_async</code> in the Button, where <code>open_async</code> was declared like so <code>async def open_async():</code>, but it gave me an error &quot;RuntimeWarning: coroutine 'open_async' was never awaited
  self.tk.mainloop(n)&quot;.
  <br> If I just used <code>def async():</code>, the code would still run synchronously, thus the UI will be unresponsive. (<code>async()</code> contains some other asynchronous operation inside too, using <code>asyncio</code> and stuff).
  <br><br>Anyone knows how to resolve this? I don't want to create threads too.
  Thanks</p>