Python module Installing
<p>I wrote this command to install NLTK python module :</p>

<pre><code>sudo pip install -U nltk
</code></pre>

<p>The first time it seemed to work well but when I wanted to test it, it didn't. So I re-wrote the command and then I got</p>

<pre><code>The directory '/Users/apple/Library/Caches/pip/http' or its parent directory is not owned by the current user and the cache has been disabled. Please check the permissions and owner of that directory. If executing pip with sudo, you may want sudo's -H flag.
</code></pre>

<p>I tried every chown command possible, I don't know what I can do more. I use a Mac OS X 10.9.5. </p>