title: Instantiate subclass from superclass
body: <p>I need to instantiate a subclass from the superclass.</p>
  
  <pre><code>class Superclass(object):
      @staticmethod
      def get_instance():
          #This should return an instance of subclass1 or subclass2
  
  class Subclass1(Superclass):
      pass
  class Subclass2(Superclass):
      pass
  </code></pre>
  
  <p>I want to write:</p>
  
  <pre><code>Subclass1.get_instance()
  </code></pre>
  
  <p>and obtain an instance of Subclass1, and same for Subclass2</p>