Answers for "why use venv python"

creating venv python3

# CREATE FOLDER FOR A PROJECT
mkdir project_folder
cd project_folder

# CREATE VIRTUAL ENVIRONMENT
python3.7 -m venv myvenv 
# or alternativelly
virtualenv myvenv --python=python3.7

# ACTIVATE VIRTUAL ENVIRONMENT
source myvenv/bin/activate

python virtual env

$ pip install virtualenv

start virtualenv

$ pip install virtualenv