title: How to install packages into specific virtualenv created by conda
body: <p>I want to install python packages after virtualenv is created by conda.
  But I got the following error, does anyone know how to install packages into virtualenv created by conda ?</p>
  
  <pre><code>/Users/jzhang/anaconda/lib/python3.5/site-packages
  (env_2) jzhangMBPr:env_2 jzhang$ conda install numpy
  Fetching package metadata .........
  
  
  CondaEnvironmentNotFoundError: Could not find environment: /Users/jzhang/anaconda/envs/env_2 .
  You can list all discoverable environments with `conda info --envs`.
  </code></pre>