title: How to prepend a path to a buildout-generated script
body: <p>Scripts generated by <code>zc.buildout</code> using <code>zc.recipe.egg</code>, on our <code>&lt;package&gt;/bin/</code> directory look like this:</p>
  
  <pre><code>#! &lt;python shebang&gt; -S
  
  import sys
  sys.path[0:0] = [
      ... # some paths derived from the eggs
      ... # some other paths included with zc.recipe.egg `extra-path`
  ]
  
  # some user initialization code from zc.recipe.egg `initialization`
  
  # import function, call function
  </code></pre>
  
  <p>What I have not been able to was to find a way to <em>programmatically</em> <strong>prepend</strong> a path at the <code>sys.path</code> construction introduced in every script. Is this possible?</p>
  
  <p>Why: I have a version of my python project installed globally and another version of it installed locally (off-buildout tree). I want to be able to switch between these two versions.</p>
  
  <p>Note: Clearly, one can use the <code>zc.recipe.egg</code>/<code>initialization</code> property to add something like:</p>
  
  <pre><code>initialization = sys.path[0:0] = [ /add/path/to/my/eggs ]
  </code></pre>
  
  <p>But, is there any other way? Extra points for an example! </p>