How to automatically activate virtualenvs when cd'ing into a directory

Question

I have a bunch of projects in my ~/Documents. I work almost exclusively in python, so these are basically all python projects. Each one, e.g. ~/Documents/

Answer 1

This is my solution:

1. If VIRTUAL_ENV is not set then:
   1. Check if we're inside a virtual env
   2. If yes, then activate it
2. Else (VIRTUAL_ENV is defined), check that the current folder starts with $VIRTUAL_ENV (removing the /venv part) and verify that the deactivate command exists
   1. Deactivate teh environment

This is the script:

function cd() {
  builtin cd $1

  if [[ -z "${VIRTUAL_ENV}" ]]; then
    if [[ -d ./venv && -f ./venv/bin/activate ]]; then
      source ./venv/bin/activate
    fi
  elif [[ ! "$(pwd)" == ${VIRTUAL_ENV:0:n-5}* && ! -z "$(command -v deactivate)" ]]; then
    deactivate
  fi
}

Note: You need to add this to .bashrc. If it doesn't work, check if your .profile is not overriding your command (it happened to me)