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()