ImportError: cannot import name ‘PILLOW

报错：

(eff) ubuntu@mcj:~/eff$ python efficientdet_test.py 
Traceback (most recent call last):
  File "efficientdet_test.py", line 11, in <module>
    from backbone import EfficientDetBackbone
  File "/home/ubuntu/eff/backbone.py", line 8, in <module>
    from efficientdet.model import BiFPN, Regressor, Classifier, EfficientNet
  File "/home/ubuntu/eff/efficientdet/model.py", line 3, in <module>
    from torchvision.ops.boxes import nms as nms_torch
  File "/home/ubuntu/anaconda3/envs/eff/lib/python3.6/site-packages/torchvision/__init__.py", line 4, in <module>
    from torchvision import datasets
  File "/home/ubuntu/anaconda3/envs/eff/lib/python3.6/site-packages/torchvision/datasets/__init__.py", line 9, in <module>
    from .fakedata import FakeData
  File "/home/ubuntu/anaconda3/envs/eff/lib/python3.6/site-packages/torchvision/datasets/fakedata.py", line 3, in <module>
    from .. import transforms
  File "/home/ubuntu/anaconda3/envs/eff/lib/python3.6/site-packages/torchvision/transforms/__init__.py", line 1, in <module>
    from .transforms import *
  File "/home/ubuntu/anaconda3/envs/eff/lib/python3.6/site-packages/torchvision/transforms/transforms.py", line 17, in <module>
    from . import functional as F
  File "/home/ubuntu/anaconda3/envs/eff/lib/python3.6/site-packages/torchvision/transforms/functional.py", line 5, in <module>
    from PIL import Image, ImageOps, ImageEnhance, PILLOW_VERSION
ImportError: cannot import name 'PILLOW_VERSION'