define virtual environment code example
Example 1: virtual env in python
pip install --user virtualenv
py -m venv env
.\env\Scripts\activate
Example 2: python virtual env
$ export VIRTUALENVWRAPPER_PYTHON=/usr/bin/python2.7
pip install --user virtualenv
py -m venv env
.\env\Scripts\activate
$ export VIRTUALENVWRAPPER_PYTHON=/usr/bin/python2.7