start vir env in 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: create a venv

# Create the virtual environment.
python -m venv venv

# Activate the env.
venv\Scripts\activate.bat

Example 3: activate venv in python

tutorial-env\Scripts\activate.bat