Instantiate subclass from superclass
<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>
