title: Jupyter using the wrong version of python
body: <p>Hi I've installed python 2.7 but did not remove 2.6. i've added 2.7 to the path and also as an alias but it seems like when I do jupyter notebook it tries to access 2.6</p>
  
  <pre><code>&gt; jupyter notebook
  Traceback (most recent call last):
  File "jupyter-notebook", line 7, in &lt;module&gt;
   from notebook.notebookapp import main
   File "/usr/lib/python2.6/site-packages/notebook/__init__.py", line 25, in &lt;module&gt;
  from .nbextensions import install_nbextension
  File "/usr/lib/python2.6/site-packages/notebook/nbextensions.py", line 226, in  &lt;module&gt;
  from traitlets import Bool, Enum, Unicode
  File "/usr/lib/python2.6/site-packages/traitlets/__init__.py", line 1, in &lt;module&gt;
  from .traitlets import *
  File "/usr/lib/python2.6/site-packages/traitlets/traitlets.py", line 1291
  return {n: t for (n, t) in cls.class_traits(**metadata).items()
                 ^
  </code></pre>
  
  <p>My python version seems to point to 2.7</p>
  
  <pre><code>$ python --version
  Python 2.7.6
  </code></pre>
  
  <p>as well as my which python seems to give the right out put :</p>
  
  <pre><code>$ which python
  alias python='/usr/local/bin/python2.7'
  /usr/local/bin/python2.7
  </code></pre>
  
  <p>I have pip installed for both versions of python. I am not sure how to fix this :( </p>