title: What is the difference between pip install and sudo pip install?
body: <p>I tried installing Flask and a few packages using sudo in a virtual environment, but on trying to import Flask, it'll throw up an ImportError. On installing the same packages with <code>pip install</code> though it works fine. 
  So what's the difference between these methods? I tried this on Ubuntu. </p>
  
  <p>Also, where does pip install these packages? Looking through Stack Overflow I could only find questions that answer how to list packages installed by pip, but not where to find them (in context to the virtual environment)</p>