title: Install SimpleElastix for Python3 on macOS
body: <p>I am using macOS Sierra 10.12.6, trying to install the SimpleElastix extension of SimpleITK. I have been following the instructions <a href="http://simpleelastix.readthedocs.io/GettingStarted.html" rel="nofollow noreferrer">here</a>. After I got it to work, it turned out the extension seems to be only included in SimpleITK when I use Python 2.7, but not when I use Python 3.6 in the sense that when I try </p>
  
  <pre><code>import SimpleITK as sitk
  resultImage = sitk.Elastix(sitk.ReadImage("fixedImage.nii"), sitk.ReadImage("movingImage.nii"))
  </code></pre>
  
  <p>I get the error </p>
  
  <pre><code>AttributeError: module 'SimpleITK' has no attribute 'Elastix'
  </code></pre>
  
  <p>I have found this <a href="https://github.com/rcasero/pysto/wiki/Build-and-install-SimpleElastix-for-python-3.x" rel="nofollow noreferrer">suggestion</a> but have not been able to get it to work on my Mac.</p>
  
  <p>Thanks for any advice,</p>
  
  <p>TomD</p>