title: How to modify `numpy` code and rebuild and use it?
body: <p>Normally, my <code>numpy</code> is located on </p>
  
  <pre><code>/Library/Python/2.7/site-packages/numpy 
  </code></pre>
  
  <p>And i download the new one from website to modify some function of numpy then build and install it. </p>
  
  <p>For this <code>modified numpy</code> is located on </p>
  
  <pre><code>/opt/local/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/numpy
  </code></pre>
  
  <p>And, my <code>$PYTHONPATH</code> had both</p>
  
  <p><code>/Library/Python/2.7/site-packages/</code> </p>
  
  <p>and </p>
  
  <p><code>/opt/local/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages</code></p>
  
  <p>I think this is confusing.</p>
  
  <p>My question is how can i use my <code>modified numpy</code> instead of the original numpy in my project?</p>
  
  <p>Finally, My point is i just want to use my <code>modified numpy</code> in my project. And in the same time i don't want to mixed up my modified code to the original code of numpy. What's the best way to manage the multiple version of numpy? </p>