default value of parameter as result of instance method
<p>I would like to initialize method parameter by some default value, if explicit value was not passing in the method.  Something like this:</p>

<pre><code>class Example
   def __init__(self, data = self.default_data()):
      self.data = data

   def default_data():
      # ....
      return something
</code></pre>

<p>But I get the error:</p>

<pre><code>NameError: name 'self' is not defined
</code></pre>

<p>How can I fix it?</p>
