pyenv versions # show installed versions
pyenv install --list | grep " 3\.[6]" # show available versions for prefix
pyenv install 3.6.8 # install specific version
pyenv global 3.6.8 # set global
pyenv local 3.6.8 # set local
pyenv shell 3.8-dev # set shell
python3 -m venv venv # create
# or
python3 -m venv venv --without-pip # if above throws segmentation error
source venv/bin/activate # activate