title: ImportError: No module named 'tensorflow.python' with tensorflow-gpu
body: <p>I wanted to have gpu-support for keras/tensorflow, thats why I installed tensorflow-gpu.
  So I installed tensorflow-gpu through pip: </p>
  
  <blockquote>
    <p>pip install --upgrade tensorflow-gpu</p>
  </blockquote>
  
  <p>This leads to this:</p>
  
  <pre><code>from keras import backend as K
  K.tensorflow_backend._get_available_gpus()
  &gt; []
  </code></pre>
  
  <p>Then I found <a href="https://stackoverflow.com/questions/45171766/keras-tensorflow-backend-does-not-detect-gpu">this stackoverflow answer</a> which stated I should uninstall tensorflow after installing tensorflow-gpu. This leads to this:</p>
  
  <pre><code>Using TensorFlow backend.
  ---------------------------------------------------------------------------
  ImportError                               Traceback (most recent call last)
  &lt;ipython-input-1-3d00d838479b&gt; in &lt;module&gt;()
  ----&gt; 1 from keras import backend as K
        2 K.tensorflow_backend._get_available_gpus()
  
  /raid/ntzioras/VirtualEnvironments/DeepLearning/lib/python3.4/site-packages/keras/__init__.py in &lt;module&gt;()
        1 from __future__ import absolute_import
        2 
  ----&gt; 3 from . import utils
        4 from . import activations
        5 from . import applications
  
  /raid/ntzioras/VirtualEnvironments/DeepLearning/lib/python3.4/site-packages/keras/utils/__init__.py in &lt;module&gt;()
        4 from . import data_utils
        5 from . import io_utils
  ----&gt; 6 from . import conv_utils
        7 
        8 # Globally-importable utils.
  
  /raid/ntzioras/VirtualEnvironments/DeepLearning/lib/python3.4/site-packages/keras/utils/conv_utils.py in &lt;module&gt;()
        7 from six.moves import range
        8 import numpy as np
  ----&gt; 9 from .. import backend as K
       10 
       11 
  
  /raid/ntzioras/VirtualEnvironments/DeepLearning/lib/python3.4/site-packages/keras/backend/__init__.py in &lt;module&gt;()
       82 elif _BACKEND == 'tensorflow':
       83     sys.stderr.write('Using TensorFlow backend.\n')
  ---&gt; 84     from .tensorflow_backend import *
       85 else:
       86     raise ValueError('Unknown backend: ' + str(_BACKEND))
  
  /raid/ntzioras/VirtualEnvironments/DeepLearning/lib/python3.4/site-packages/keras/backend/tensorflow_backend.py in &lt;module&gt;()
        4 
        5 import tensorflow as tf
  ----&gt; 6 from tensorflow.python.training import moving_averages
        7 from tensorflow.python.ops import tensor_array_ops
        8 from tensorflow.python.ops import control_flow_ops
  
  ImportError: No module named 'tensorflow.python'
  </code></pre>
  
  <p>Reeinstalling tensorflow with </p>
  
  <blockquote>
    <p>pip install --upgrade tensorflow --no-cache</p>
  </blockquote>
  
  <p>leads again to an empty array for the gpus with the code above.</p>
  
  <p>Any ideas how to fix this?</p>