我在试着运行代码

import keras

我得到了这个堆栈跟踪。我试过重新安装keras和tensorflow，但是没有任何效果。这是堆栈跟踪。

ModuleNotFoundError                       Traceback (most recent call last)
<ipython-input-10-88d96843a926> in <module>
----> 1 import keras

~\Anaconda3\lib\site-packages\keras\__init__.py in <module>
      1 from __future__ import absolute_import
      2 
----> 3 from . import utils
      4 from . import activations
      5 from . import applications

~\Anaconda3\lib\site-packages\keras\utils\__init__.py in <module>
      4 from . import data_utils
      5 from . import io_utils
----> 6 from . import conv_utils
      7 from . import losses_utils
      8 from . import metrics_utils

~\Anaconda3\lib\site-packages\keras\utils\conv_utils.py in <module>
      7 from six.moves import range
      8 import numpy as np
----> 9 from .. import backend as K
     10 
     11 

~\Anaconda3\lib\site-packages\keras\backend\__init__.py in <module>
----> 1 from .load_backend import epsilon
      2 from .load_backend import set_epsilon
      3 from .load_backend import floatx
      4 from .load_backend import set_floatx
      5 from .load_backend import cast_to_floatx

~\Anaconda3\lib\site-packages\keras\backend\load_backend.py in <module>
     88 elif _BACKEND == 'tensorflow':
     89     sys.stderr.write('Using TensorFlow backend.\n')
---> 90     from .tensorflow_backend import *
     91 else:
     92     # Try and load external backend.

ModuleNotFoundError: No module named 'keras.backend.tensorflow_backend'