work on virtual environment python code example

Example 1: python virtual environment

python3 -m venv env
python -m virtualenv env #py2

source env/bin/activate

#all this is on same directory

Example 2: virtual env in python

pip install --user virtualenv
py -m venv env
.\env\Scripts\activate

Example 3: python venv usage

python3 -m venv /path/to/new/virtual/environment

Example 4: how to activate venv python

python3 -m venv tutorial-env