Error in python after 'import tensorflow': Error in python after 'import tensorflow':

Question

I installed tensorflow with command:

pip install /tmp/tensorflow_pkg/tensorflow-0.6.0-cp27-none-linux_x86_64.whl

But a got this error when I run import tensorflow.

import tensorflow
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 37, in <module>
    from tensorflow.core.framework.graph_pb2 import *
  File "/usr/local/lib/python2.7/dist-packages/tensorflow/core/framework/graph_pb2.py", line 10, in <module>
    from google.protobuf import descriptor_pb2
  File "/usr/local/lib/python2.7/dist-packages/google/protobuf/descriptor_pb2.py", line 1533, in <module>
    __module__ = 'google.protobuf.descriptor_pb2'
  File "/usr/local/lib/python2.7/dist-packages/google/protobuf/reflection.py", line 123, in __new__
    new_class = superclass.__new__(cls, name, bases, dictionary)
TypeError: metaclass conflict: the metaclass of a derived class must be a (non-strict) subclass of the metaclasses of all its bases