title: Python3: access a dunder variable
body: <p>I know what Python dunder variables are, and I'm aware of name mangling.</p>
  
  <p>But for some reason I can't access the dunder variable in the following code snippet: </p>
  
  <pre><code>    for node in ast.find_all((Call,)):
          # Check if the identifier match the extension name
          if node.node.identifier == 'myapp.ext.MyExtension':
              # I want to access node.__meta
              print("==&gt; type(node) = %s" % type(nod))
              print("==&gt; node.__dict__ = %s" % node.__dict__")
  </code></pre>
  
  <p>Which prints:</p>
  
  <pre><code>==&gt; type(node) = &lt;class 'jinja2.nodes.Call'&gt;
  ==&gt; node.__dict__ = {
          'kwargs': [],
          # ... a bunch of other attributes
          # The __meta attribute below is what I want to access
          '__meta': {'type': 'checkbox', 'value': Const(value='checked'), 'name': Const(value='agree'), 'class': Const(value='bold')}
      }
  </code></pre>
  
  <p>Since the <code>node</code> variable is an instance of the <code>Call</code> class, and I want to access its <code>__meta</code> attribute, according to name mangling, I'd have to do it like this <code>node._Call__meta</code>, but I'm getting an error:</p>
  
  <pre><code>`'Call' object has no attribute '_Call__meta'`
  </code></pre>
  
  <p>What am I doing wrong?</p>