ubuntu 安装 GPU 版tensorflow出现的错误

Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/usr/local/lib/python2.7/dist-packages/tensorflow/__init__.py", line 23, in <module>
    from tensorflow.python import *
  File "/usr/local/lib/python2.7/dist-packages/tensorflow/python/__init__.py", line 53, in <module>
    from tensorflow.core.framework.graph_pb2 import *
  File "/usr/local/lib/python2.7/dist-packages/tensorflow/core/framework/graph_pb2.py", line 9, in <module>
    from google.protobuf import symbol_database as _symbol_database
  File "/usr/local/lib/python2.7/dist-packages/google/protobuf/symbol_database.py", line 164, in <module>
    _DEFAULT = SymbolDatabase(pool=descriptor_pool.Default())
AttributeError: 'module' object has no attribute 'Default'

方法：

sudo pip install --upgrade protobuf