title: Getting Error: 'No module named flask' in VSCode even when I have installed flask
body: <p>I want to debug an application using Python and Flask in VSCode. I have installed Flask and the app runs perfectly fine through cmd. But, when I try to debug it through VSCode, it gives the following error:</p>
  
  <pre><code>cd 'c:\Users\Aditi\CleanHandymanApp'; 
  ${env:FLASK_APP}='NewApp'; ${env:PYTHONIOENCODING}='UTF-8'; 
  ${env:PYTHONUNBUFFERED}='1'; &amp; 'C:\Users\Aditi\envs\CleanHandymanApp\Scripts\python.exe' 
  'c:\Users\Aditi\.vscode\extensions\ms-python.python-2018.10.1\pythonFiles\experimental\ptvsd_launcher.py' '--client' '--host' 
  'localhost' '--port' '63143' '-m' 'flask' 'run' '--no-debugger' '--no-reload'
  No module named flask
  </code></pre>
  
  <p>Can you please help me.</p>