class Loginpanel():
    def __init__(self):
        builder=gtk.Builder()
        builder.add_from_file('a.glade')
        builder.connect_signals(self)
       
        for widget in builder.get_objects():
            if issubclass(type(widget),gtk.Buildable):   #测试是否继承关系
                name=gtk.Buildable.get_name(widget)
                setattr(self,name,widget)  #setattr(x,'a',1)等价于x.a = 1

    def on_login_clicked(self,widget,data=None):
        print self.main_window
        self.main_window.remove(self.vbox_login)

if __name__=='__main__':
    Loginpanel().main_window.show()
    gtk.main()