title: How can I tell if I have tensorflow-gpu installed using python?
body: <p>I am trying to differentiate within python whether a user has installed <code>tensorflow-gpu</code> or just <code>tensorflow</code> (on the CPU, which lacks GPU support).</p>
  
  <p>I do not want to have to run a trivial model (with <code>log_device_placement</code>) to have to figure that out.</p>
  
  <p>I have tried making use of <code>tensorflow.__version__</code>, but it seems like <code>1.3.0-rc2</code> is printed both ways.</p>