get Train.py Run problem

[Troyella]

!python train.py

Traceback (most recent call last):
  File "train.py", line 2, in <module>
    from data import *
  File "/_zhangyongleth4/repulsion_loss_ssd/data/__init__.py", line 1, in <module>
    from .voc0712 import VOCDetection, VOCAnnotationTransform, VOC_CLASSES, VOC_ROOT
ImportError: cannot import name 'VOC_ROOT'

when I followed your steps,I got an error