title: Python3 not taking environment variables set by source command
body: <p>I have written a config file as follows:</p>
  
  <p><code>bucket_name=some-bucket</code></p>
  
  <p>I run the command <code>source config_de_local</code> where config_de_local is the file name in which variables to be set are stored.</p>
  
  <p>Then I run the command: <code>echo $bucket_name</code> and I get the o/p: <code>some-bucket</code>.
  However, the config file is still not able to import any variable, it states all as null. This is how I am importing a variable:
  <code>bucket_name = os.getenv('bucket_name', '')</code></p>
  
  <p>However, in the terminal, if I run the command: <code>export bucket_name=some-bucket</code> and then in Python3 shell, I run the line: <code>print(os.getenv('bucket_name',''))</code> I get the desired output.</p>
  
  <p>Note: I am running Python3 in a virtualenv; I activate it and then set my env variables via <code>source</code> and <code>export</code>.</p>