title: python-dev installation error: ImportError: No module named apt_pkg
body: <p>I am Debian user, and I want to install python-dev, but when I run the code in the shell as a root:</p>
  
  <pre><code># aptitude install python-dev
  </code></pre>
  
  <p>I get the following error:</p>
  
  <pre><code>Traceback (most recent call last):       
    File "/usr/bin/apt-listchanges", line 28, in &lt;module&gt;
      import apt_pkg
  ImportError: No module named apt_pkg
  </code></pre>
  
  <p>What seems to be the problem and how can I resolve it?</p>