venv | helper

venv.sh

venv() {
  USAGE_INFO="Usage: venv [ -h | create [ ENV_NAME [ --overwrite ] ] | delete | activate | list | update ]"

  DIR_ALREADY_EXISTS="A virtual environment / directory already exists with that name. Use --overwrite flag to overwrite it."
  NOT_IN_VENV="This command is only allowed in a virtual environment."
  VENV_DIR_NOT_SET="VENV_DIR environment variable is not set."
  VENV_PYVER_NOT_SET="VENV_PYVER environment variable is not set."

  VENV_CREATED="Virtual environment created"
  VENV_DELETED="Virtual environment deleted"
  VENV_ACTIVATED="Virtual environment activated"
  VENV_LIST="Available virtual environments: "

  ARG_HELP="-h"
  ARG_CREATE="create"
  ARG_DELETE="delete"
  ARG_ACTIVATE="activate"
  ARG_LIST="list"
  ARG_UPDATE="update"
  ARG_OVERWRITE="--overwrite"

  IN_VENV=$(type deactivate 2>/dev/null | head -n 1 | grep -c function)

  # sanity checks
  if [ -z "$1" ] || [ "$1" = "$ARG_HELP" ]; then echo "$USAGE_INFO" && echo && return; fi
  if [ -z "$VENV_DIR" ] || [ -z "$VENV_PYVER" ]; then
    ([ -z "$VENV_DIR" ] && echo "$VENV_DIR_NOT_SET")
    ([ -z "$VENV_PYVER" ] && echo "$VENV_PYVER_NOT_SET")
    echo
    return
  fi

  # logic
  if [ "$1" = "$ARG_CREATE" ] && [ ! -z "$2" ]; then
    [ "$3" = "$ARG_OVERWRITE" ] && rm -rf $VENV_DIR/$2
    ([ -d "$VENV_DIR/$2" ] && echo $DIR_ALREADY_EXISTS) || (python$VENV_PYVER -m venv $VENV_DIR/$2 && echo "$VENV_CREATED - $2")
  elif [ "$1" = "$ARG_DELETE" ] && [ ! -z "$2" ]; then
    [ "$IN_VENV" -eq 1 ] && deactivate
    rm -rf $VENV_DIR/$2 && echo "$VENV_DELETED - $2"
  elif [ "$1" = "$ARG_ACTIVATE" ] && [ ! -z "$2" ]; then
    source $VENV_DIR/$2/bin/activate && echo "$VENV_ACTIVATED - $2"
  elif [ "$1" = "$ARG_LIST" ]; then
    echo "$VENV_LIST" && (ls -1 $VENV_DIR | xargs -I {} sh -c 'printf "\t* {} ($($VENV_DIR/{}/bin/python -V | cut -d " " -f 2))\n"')
  elif [ "$1" = "$ARG_UPDATE" ]; then
    [ "$IN_VENV" -eq 1 ] && (pip list --format=freeze | cut -d "=" -f 1 | xargs -I {} pip install --upgrade {}) || echo "$NOT_IN_VENV"
  else
    echo "$USAGE_INFO"
  fi
  echo
}

Instructions

• Add this function to your .bashrc, .zshrc, or .profile. You can also download this file, and source it in one of them (source <filename>)
• Set $VENV_DIR to an existing directory where you want to create your virtual environments in.
• Set $VENV_PYVER to the python version you plan to use. E.g., if you set VENV_PYVER=XXX, then it runs pythonXXX.

Compatibility

• MacOS 10.15 - OK
• Ubuntu 18.04 - OK