use python2 for create virtualenv code example

Example 1: how to set up python virtual environment

# install the package virtualenv
pip install virtualenv

# setup envioronment for Data engineering pipeline
virtualenv dataengineer_pipeline

# if using python >= 3.3
python -m venv dataengineer_pipeline

# start the environment in linux using 
dataengineer_pipeline/bin/activate

# or in windows
dataengineer_pipeline\Scripts\activate.bat

# when you are done using the environment, type in the command below
deactivate

Example 2: how to create a new virtualenv

to make a new virtualenv: 
virtualenv env_name

             to activate this virtual environment:
source env_name/bin/activate (on mac and linux)
source env_name/Scripts/activate (on windows)