how to use env on 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: create a virtualenv python

pip install virtualenv
cd projectfolder #go to project folder
virtualenv projectname #create the folder projectname 
source projectname/bin/activate