title: How to use pip 1.5 (on Python) to install and later upgrade externally hosted package repositories?
body: <p>Let us take the example of <a href="https://pypi.python.org/pypi/py-dom-xpath" rel="nofollow">https://pypi.python.org/pypi/py-dom-xpath</a>. In this case the package repository is hosted in <a href="http://code.google.com/p/py-dom-xpath/" rel="nofollow">http://code.google.com/p/py-dom-xpath/</a>.</p>
  
  <p>I am using Python 2.7 on Windows 7.</p>
  
  <blockquote>
    <p>pip install py-dom-xpath</p>
  </blockquote>
  
  <pre><code>Downloading/unpacking py-dom-xpath
    Could not find any downloads that satisfy the requirement py-dom-xpath
    Some externally hosted files were ignored (use --allow-external py-dom-xpath to allow).
  Cleaning up...
  No distributions at all found for py-dom-xpath
  Storing debug log for failure in C:\Users\insrkum\pip\pip.log
  </code></pre>
  
  <blockquote>
    <p>pip install --allow-external py-dom-xpath</p>
  </blockquote>
  
  <pre><code>You must give at least one requirement to install (see "pip help install")
  </code></pre>
  
  <blockquote>
    <p>pip install --allow-all-external py-dom-xpath</p>
  </blockquote>
  
  <pre><code>Downloading/unpacking py-dom-xpath
    Could not find any downloads that satisfy the requirement py-dom-xpath
    Some insecure and unverifiable files were ignored (use --allow-unverified py-dom-xpath to allow).
  Cleaning up...
  No distributions at all found for py-dom-xpath
  Storing debug log for failure in C:\Users\insrkum\pip\pip.log
  </code></pre>
  
  <p>I attempted use --index-url option without any success. What works is the following command</p>
  
  <blockquote>
    <p>pip install <a href="http://py-dom-xpath.googlecode.com/files/py-dom-xpath-0.1.tar.gz" rel="nofollow">http://py-dom-xpath.googlecode.com/files/py-dom-xpath-0.1.tar.gz</a></p>
  </blockquote>
  
  <p>This is not the best way to install externally hosted package repositories. I am interested to use --allow-external or --allow-all-external.
  I also want to learn how to use --upgrade option with externally hosted package repositories.</p>