title: numpy imported successfully on command line but not on IDLE
body: <p>I can import numpy successfully using my python version 2.7.11 on the command line :  <a href="https://i.stack.imgur.com/LKVF2.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/LKVF2.png" alt="enter image description here"></a></p>
  
  <p>but not in IDLE where I get the following error : </p>
  
  <pre><code>Traceback (most recent call last):
    File "/Users/macbookpro/Desktop/Python learning/Mortgages/mortgage_plot.py", line 2, in &lt;module&gt;
      import pylab
    File "/Users/macbookpro/Library/Python/2.7/lib/python/site-packages/pylab.py", line 1, in &lt;module&gt;
      from matplotlib.pylab import *
    File "/Users/macbookpro/Library/Python/2.7/lib/python/site-packages/matplotlib/__init__.py", line 124, in &lt;module&gt;
      from . import cbook
    File "/Users/macbookpro/Library/Python/2.7/lib/python/site-packages/matplotlib/cbook/__init__.py", line 35, in &lt;module&gt;
      import numpy as np
  ImportError: No module named numpy
  </code></pre>
  
  <p><a href="https://i.stack.imgur.com/uGLv2.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/uGLv2.png" alt="enter image description here"></a></p>
  
  <p>What could be the source of this problem ?</p>