Install

Find the path of the version of python that you want to use

which python

Find the path of virtualenvwrapper.sh

find / -name virtualenvwrapper.sh

/home/lingxt/.local/bin/virtualenvwrapper.sh

Edit the .bashrc file

export WORKON_HOME=$HOME/.virtualenvs
export VIRTUALENVWRAPPER_PYTHON=/usr/bin/python3.7
source /usr/local/bin/virtualenvwrapper.sh
export VIRTUALENVWRAPPER_ENV_BIN_DIR=bin 

install virtualenv and virtualenvwrapper

sudo pip3 install virtualenv virtualenvwrapper

Use

Check the list of environment

workon

Create new environment

mkvirtualenv env_name -p path_to_python

Reference

1. https://towardsdatascience.com/installing-opencv-3-4-3-on-raspberry-pi-3-model-b-e9af08a9f1d9