title: 'Can't set attribute' with new-style properties in Python
body: <p>I'm trying to use new-style properties declaration:</p>
  
  <pre><code>class C(object):
      def __init__(self):
          self._x = 0
  
      @property
      def x(self):
          print 'getting'
          return self._x
  
      @x.setter
      def set_x(self, value):
          print 'setting'
          self._x = value
  
  if __name__ == '__main__':
      c = C()
      print c.x
      c.x = 10
      print c.x
  </code></pre>
  
  <p>and see the following in console:</p>
  
  <pre><code>pydev debugger: starting
  getting
  0
  File "\test.py", line 55, in &lt;module&gt;
  c.x = 10
  AttributeError: can't set attribute
  </code></pre>
  
  <p>what am I doing wrong?
  P.S.: Old-style declaration works fine.</p>