title: Cannot import tkinter after installing Python 3 with pyenv
body: <p>I got problems with importing <code>tkinter</code> after installing Python version 3.4.2 with <code>pyenv</code>. My system Python is version 2.7.6. I am using Ubuntu 14.04. For the following sample script <code>t.py</code>:</p>
  
  <pre><code>import _tkinter
  
  print ("Hello")
  </code></pre>
  
  <p>I get:</p>
  
  <pre><code>$ pyenv global system
  $ python --version
  Python 2.7.6
  $ python t.py
  Hello
  $ pyenv global 3.4.2
  $ python --version
  Python 3.4.2
  $ python t.py
  Traceback (most recent call last):
    File "t.py", line 3, in &lt;module&gt;
      import _tkinter
  ImportError: No module named '_tkinter'
      Traceback (most recent call last):
        File "t.py", line 3, in &lt;module&gt;
          import _tkinter
      ImportError: No module named '_tkinter'
  </code></pre>
  
  <p>Note that <code>pyenv</code> installed Python version 3.4.2 in <code>~/.pyenv/versions/3.4.2/</code>.</p>