listdir里的ext_filters，传参报错

[CGguocheng]

result = (f for f in result if f.ext.lower() in ext_filters)
AttributeError: 'str' object has no attribute 'ext'

result为os.listdir的结果，类型为字符串，没有ext

[Wenfeng-Zhang]

修改为:

        if ext_filters:
            result = (f for f in result if self.pathlib.isfile(self.child(f)) and DayuPath(f).ext.lower() in ext_filters)