title: Why can't tensorflow be imported?
body: <p>I just installed Tensorflow, and am trying to run a <a href="https://www.tensorflow.org/install/install_linux#ValidateYourInstallation" rel="nofollow noreferrer">test program</a> in Python to validate the installation. When I run the program usually nothing happens. A couple times the Spyder IDE has crashed. Here is the test program:</p>
  
  <pre><code>print('test before')
  import tensorflow as tf
  print('test after')
  hello = tf.constant('Hello, TensorFlow!')
  sess = tf.Session()
  print(sess.run(hello))
  </code></pre>
  
  <p>Interestingly, all lines before importing tensorflow run, that is "test before" is printed. However, the program seems to run into trouble with importing tensorflow because "test after" is not printed. Why can't the program successfully import tensorflow?</p>
  
  <p>Also, note that the tensorflow installation seems to have been successful  because at the end it printed "Successfully installed tensorflow-1.7.0". And no errors appear when running the program. Usually if there is a problem when importing the package you get an error saying something like "[package] cannot be found". In this case the program just runs for a few seconds and then stops (or the IDE crashes) without returning an error. When running <code>python3 -c 'import tensorflow'</code> it gave the error <code>Illegal instruction (core dumped)</code>.</p>
  
  <p>Tensorflow version: 1.7.0
  Python version: 3.5.2
  using Spyder IDE
  Operating system: ubuntu 16.04 LTS</p>