Answers for "how to run virtualenv"

how to create virtual environment

# for windows 10

py -m venv myvirtualenv
myvirtualenvScriptsactivate #!!!! use "" not "/" !!!!!

how to use virtual environment python

python3 -m venv env

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)