title: Select method to execute inside thread before starting thread
body: <p>I created a small flask app to download images and text from pages, this can take verly long time, so
  I would like to execute my requests in parell. I create threaded tasks. I would like this tasks to be able to download text or images from sites. I keep my tasks in a list of workers. 
  However I would like to select a method which thread will execute and then start whole thread.
  How can I pass my method to thread run method()? Will this be a sub daemon thread?</p>
  
  <pre class="lang-py prettyprint-override"><code>import threading
  import time
  
  workers = []
  
  class SavePage:
      def get_text(self):
          print("Getting text")
  
      def get_images(self):
          print("Getting images")
  
  
  class Task(threading.Thread):
      def __init__(self):
          super().__init__()
          self.save_page = SavePage()
  
      def get_text_from_page(self):
          self.save_page.get_text()
  
      def get_images_from_page(self):
          self.save_page.get_images()
  
  
  if __name__ == '__main__':
      task = Task()
  
      task.get_images_from_page()  # Why this executes, when I didn't put task.start() ?
      # Moreover, is this really threaded? or just uses a method from class Task?
  
      workers.append(task)  # I want this list to be empty, after job is finished
      print("".join(str(worker.is_alive()) for worker in workers))  #
      print(workers)
  
  </code></pre>