repeat the function

class Content(Screen):
    def on_enter(self):
        self.set_animation()

    def set_animation(self,*args):
        anim=Animation(opacity=1,duration=1)
        anim+=Animation(opacity=1,duration=7)
        anim+=Animation(opacity=0,duration=7)
        #self.anim.repeat = True
        anim.start(self.ids.bg)
        anim.bind(on_complete=self.comp)

    def comp(self,*args):
        self.ids.bg.source='images/1.jpg'
        anim=Animation(opacity=1,duration=1)
        anim+=Animation(opacity=1,duration=7)
        anim+=Animation(opacity=0,duration=7)
        anim.start(self.ids.bg)
        anim.bind(on_complete=self.compl)

    def compl(self,*args):
        self.ids.bg.source='images/2b.jpg'
        anim=Animation(opacity=1,duration=1)
        anim+=Animation(opacity=1,duration=7)
        anim+=Animation(opacity=0,duration=7)
        anim.start(self.ids.bg)
        anim.repeat = True