title: pip install for Python 3 in virtualenv on Mac OSX?
body: <p>I can <code>pip install</code> and <code>import</code> just about any package on my Mac in a virtual environment, doing the following:</p>
  
  <p>Setting up the virtual environment:</p>
  
  <pre><code>Last login: Mon Oct  3 18:47:06 on ttys000
  me-MacBook-Pro-3:~ me$ cd /Users/me/Desktop/
  me-MacBook-Pro-3:Desktop me$ virtualenv env
  New python executable in /Users/me/Desktop/env/bin/python
  Installing setuptools, pip, wheel...done.
  me-MacBook-Pro-3:Desktop me$ source env/bin/activate
  </code></pre>
  
  <p>Let's <code>pip install</code> pandas:</p>
  
  <pre><code>(env) me-MacBook-Pro-3:Desktop me$ pip install pandas
  Collecting pandas
    Using cached pandas-0.19.0-cp27-cp27m-macosx_10_6_intel.macosx_10_9_intel.macosx_10_9_x86_64.macosx_10_10_intel.macosx_10_10_x86_64.whl
  Collecting pytz&gt;=2011k (from pandas)
    Using cached pytz-2016.7-py2.py3-none-any.whl
  Collecting python-dateutil (from pandas)
    Using cached python_dateutil-2.5.3-py2.py3-none-any.whl
  Collecting numpy&gt;=1.7.0 (from pandas)
    Using cached numpy-1.11.1-cp27-cp27m-macosx_10_6_intel.macosx_10_9_intel.macosx_10_9_x86_64.macosx_10_10_intel.macosx_10_10_x86_64.whl
  Collecting six&gt;=1.5 (from python-dateutil-&gt;pandas)
    Using cached six-1.10.0-py2.py3-none-any.whl
  Installing collected packages: pytz, six, python-dateutil, numpy, pandas
  Successfully installed numpy-1.11.1 pandas-0.19.0 python-dateutil-2.5.3 pytz-2016.7 six-1.10.0
  </code></pre>
  
  <p>Great! Now, let's see if it works in Python 2.7:</p>
  
  <pre><code>(env) me-MacBook-Pro-3:Desktop me$ python
  Python 2.7.10 (default, Oct 23 2015, 19:19:21) 
  [GCC 4.2.1 Compatible Apple LLVM 7.0.0 (clang-700.0.59.5)] on darwin
  Type "help", "copyright", "credits" or "license" for more information.
  &gt;&gt;&gt; import pandas
  &gt;&gt;&gt; exit()
  </code></pre>
  
  <p><code>pandas</code> loaded in 2.7, now let's try 3.5:</p>
  
  <pre><code>(env) me-MacBook-Pro-3:Desktop me$ python3
  Python 3.5.0a4 (v3.5.0a4:413e0e0004f4, Apr 19 2015, 14:19:25) 
  [GCC 4.2.1 (Apple Inc. build 5666) (dot 3)] on darwin
  Type "help", "copyright", "credits" or "license" for more information.
  &gt;&gt;&gt; import pandas
  Traceback (most recent call last):
    File "&lt;stdin&gt;", line 1, in &lt;module&gt;
  ImportError: No module named 'pandas'
  &gt;&gt;&gt; 
  </code></pre>
  
  <p>:(</p>
  
  <p>I'm running OSX El Capitan 10.11.6. How can I import non-builtin modules in a virtual environment? I really would rather use Python 3...</p>