How to set attributes using property decorators?

This code returns an error: AttributeError: can't set attribute This is really a pity because I would like to use properties instead of calling the methods. Does anyone know why this simple example is not working?

#!/usr/bin/python2.6


class Bar( object ):
    """ 
    ...
    """
    
    @property
    def value():
      """
      ...
      """    
      def fget( self ):
          return self._value
     
      def fset(self, value ):
          self._value = value
          
          
class Foo( object ):
    def __init__( self ):
        self.bar = Bar()
        self.bar.value = "yyy"
        
if __name__ == '__main__':
    foo = Foo()

Is this what you want?

class C(object):
    def __init__(self):
        self._x = None

    @property
    def x(self):
        """I'm the 'x' property."""
        return self._x

    @x.setter
    def x(self, value):
        self._x = value

Taken from http://docs.python.org/library/functions.html#property.