A simple guide to install virtual environment with different python version on Windows.

1. Objectives:
   1. 1. Install Virtual Environment on Windows
2. Required Tools:
   1. 1. Python —  Python 3 chosen in this case.
      2. VirtualEnv — Main virtualenv tool.
      3. VirtualEnvWrapper-Win — VirtualEnv Wrapper for Windows.
3. Steps:
   1. 1. Install python with python windows installer.
      2. Add python path to Windows PATH. Python 3 will enable this option for users. If not found, add the following two path (Python 3 sample default path )
         1. C:\Users\\AppData\Local\Programs\Python\Python36
         2. C:\Users\MyUserName\AppData\Local\Programs\Python\Python36\Scripts
      3. pip install virtualenv
      4. pip install virtualenvwrapper-win
      5. Main commands use with virtualenv wrapper in windows command prompt
         1. mkvirtualenv : create a new virtual env
         2. workon : list all the environment created
         3. workon  : Activate particular environment.
         4. deactivate: deactivate active environment
         5. rmvirtualenv : remove target environment.

Further notes 

• Most of the guide reference from Timmy Reilly’s Blog.
• To create virtualenv with specified python version
  • virtualenv -p <path/win dir of python version>
  • mkvirtualenv -p <path/win dir of python version>
• Retrieve a list of python modules installed via pip and save to requirement.txt
  • pip freeze > requirement.txt
• to install a list of required modules (from other virtual env etc)
  • pip install -r requirements.txt
• Likely python3 pip path for win10: C:\Users\xxx\AppData\Local\Programs\Python\Python39\Scripts