ImportError: attempted relative import with no known parent package

mask.py代码：

from . import _mask


  File "E:\kangcheng\python\pvanet\TFFRCNN\lib\pycocotools\mask.py", line 3, in
    from . import _mask

ImportError: attempted relative import with no known parent package

_mask 是pyd文件：

lib/pycocotools/_mask.cp36-win_amd64.pyd

修改办法：

from pycocotools import _mask