Python kivy.properties 模块，ListProperty() 实例源码

def refresh_media_id(self, *args):
        '''Updates id numbers for all files in self.media ListProperty'''
        mp = {}
        for i, x in enumerate(self.media):
            x['id'] = i
            mpath = x['path']
            if mpath in mp:
                mp[x['path']].append(i)
            else:
                mp[x['path']] = [i]
            x['playlist_name'] = self.name
            if not 'state' in x:
                x['state'] = 'normal'
        self.media_paths = mp