title: multiprocessing and tkinter
body: <p>In my class, I draw Tkinter elements, I press the right button and there is a long download of data from the Internet. At this time, the window of my program in Windows freezes=(
  I 'm trying to do this:</p>
  <pre><code>def get_data_orders_production(url):
    print(2)
    ...
    return [1, 2, 3, 4 ...]
  
  class MyApp():
    def __init__(self, root):
      self.root = root
      
    ...
    
    def check_process(self, p):
      if p.is_alive():
        print(1)
        self.root.after(2000, lambda p=p: self.check_process(p))
  
    def create_page_tk(self, flag):
      p = multiprocessing.Process(target=get_data_orders_production, args=(self.url))
      p.start()
      self.check_process(p)
      p.join()
  </code></pre>
  
  <p>When starting the function: &quot;create_page_tk&quot; - print(1) and print(2) at the same time, then the recursion does not work! Also I do not know how to return the value from the &quot;get_data_order_production&quot; function.</p>