title: Python3: ImportError: No module named '_ctypes' when using Value from module multiprocessing
body: <p>I am using Ubuntu and have installed Python 2.7.5 and 3.4.0. In Python 2.7.5 I am able to successfully assign a variable <code>x = Value('i', 2)</code>, but not in 3.4.0. I am getting:</p>
  
  <pre><code>Traceback (most recent call last):
     File "&lt;stdin&gt;", line 1, in &lt;module&gt;
     File "/usr/local/lib/python3.4/multiprocessing/context.py", line 132, in Value
        from .sharedctypes import Value
     File "/usr/local/lib/python3.4/multiprocessing/sharedctypes.py", line 10, in &lt;
  module&gt;
     import ctypes
     File "/usr/local/lib/python3.4/ctypes/__init__.py", line 7, in &lt;module&gt;
        from _ctypes import Union, Structure, Array
  ImportError: No module named '_ctypes'
  </code></pre>
  
  <p>I just updated to 3.3.2 through installing the source of 3.4.0. It installed in <em>/usr/local/lib/python3.4</em>.</p>
  
  <p>Did I update to Python 3.4 correctly?</p>
  
  <p>One thing I noticed that Python 3.4 is installed in <em>usr/local/lib</em>, while Python 3.3.2 is still installed in <em>usr/lib</em>, so it was not overwritten.</p>