title: Getting MATLAB R2019b to use Python3.6
body: <p>I am trying to use python 3.6 within the MATLAB interpreter.  I have both Python 2.7 and 3.6 installed on my machine.  When using the default python 2.7 MATLAB work fine:</p>
  
  <pre><code>&gt;&gt; pyenv('Version', '/usr/bin/python')
  
  ans =
  
  PythonEnvironment with properties:
  
        Version: "2.7"
     Executable: "/usr/bin/python"
        Library: "libpython2.7.so.1.0"
           Home: "/usr"
         Status: NotLoaded
  ExecutionMode: InProcess
  
  &gt;&gt; py.sys.version
  
  ans =
  
  Python str with no properties.
  
  2.7.5 (default, Aug  7 2019, 00:51:29)
  [GCC 4.8.5 20150623 (Red Hat 4.8.5-39)]
  </code></pre>
  
  <p>However when following MATLAB's directions to change versions of python by entering the path of the python 3 executable file, python will not load:</p>
  
  <pre><code>&gt;&gt; pyenv('Version', '/opt/rh/rh-python36/root/usr/bin/python3.6')
  
  ans =
  
   PythonEnvironment with properties:
  
        Version: "3.6"
     Executable: "/opt/rh/rh-python36/root/usr/bin/python3.6"
        Library: ""
           Home: "/opt/rh/rh-python36/root/usr"
         Status: NotLoaded
  ExecutionMode: InProcess
  
  &gt;&gt; py.sys.version
  Unable to resolve the name py.sys.version.
  </code></pre>
  
  <p>I do notice that the library field in pyenv is not filled in for python 3.  So it appears that MATLAB cannot find a python 3 shared object file.  Why would MATLAB have problems finding the libpython shared object file?</p>