use python virtual environment 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: python virtual environment

source env/bin/activate

Example 3: how to activate venv python

tutorial-env\Scripts\activate.bat

Example 4: how virtual environment in python works

>>> import sys
>>> sys.prefix
'/System/Library/Frameworks/Python.framework/Versions/3.5'