function for making Python 3 virtual env

mkvenv.sh

mkvenv()
{
    local prompt="${1:-$(basename $(pwd))}"
    shift
    command -v deactivate >/dev/null && deactivate
    [ -d .venv ] && echo "ERROR: .venv exists" 1>&2 && return 1
    python3 -m venv .venv --prompt "\[\033[1;34m\]$prompt\[\033[0m\]" $*
    activate
}