function virtualenv_prompt_info(){
    [[ -n ${VIRTUAL_ENV} ]] || return
    echo "${ZSH_THEME_VIRTUALENV_PREFIX:=[}${VIRTUAL_ENV:t}${ZSH_THEME_VIRTUALENV_SUFFIX:=]}"
  }
  
  # disables prompt mangling in virtual_env/bin/activate
  export VIRTUAL_ENV_DISABLE_PROMPT=1