title: Python - "No module named" error
body: <p>I'm working with a scientific package called TheCannon.
  It's all written in Python, and I've installed it using pip.</p>
  
  <p>Until two days ago, it worked perfectly.
  Today, when I tried to use it, this happened:</p>
  
  <pre><code>Traceback (most recent call last):
    File "test2.py", line 4, in &lt;module&gt;
      from TheCannon import dataset
  ImportError: No module named TheCannon
  </code></pre>
  
  <p>I have already uninstalled and installed it again, and nothing changed.
  Does anyone have any idea why python is not finding the package anymore and how to solve it?
  Thank you.</p>