title: python ImportError: No module named 'apt_pkg'
body: <p>when i try <code>sudo add-apt-repository ppa:webupd8team/java</code></p>
  
  <p>ubuntu terminal show this error message.</p>
  
  <pre><code>Traceback (most recent call last):
    File "/usr/bin/add-apt-repository", line 11, in &lt;module&gt;
      from softwareproperties.SoftwareProperties import SoftwareProperties
    File "/usr/lib/python3/dist-packages/softwareproperties/SoftwareProperties.py", line 27, in &lt;module&gt;
      import apt
    File "/usr/lib/python3/dist-packages/apt/__init__.py", line 21, in &lt;module&gt;
      import apt_pkg
  </code></pre>
  
  <p>though i tried <code>apt-get install python3-apt</code> but still not working(and i also tried to re-install again after removing) and i also tried <code>pip3 install apt-pkg</code> but it saying</p>
  
  <pre><code>Downloading/unpacking apt-pkg
    Could not find any downloads that satisfy the requirement apt-pkg
  No distributions at all found for apt-pkg
  Storing complete log in /home/kim/.pip/pip.log
  </code></pre>
  
  <p>and of course, import apt_pkg also not working in python3(but it is working in python2.7, i have two version of python one is 2.7 the other is 3.3)</p>
  
  <p>how can i install this package on python3 </p>