Auto activate and deactivate python venv using zsh (and fish)

When I found out about python venv (apt-get install python3-venv) I became an instant addict. It's clean, it's built-in and it's explicit.

Now every time I create a new project folder I automatically run python3 -mvenv venv && source ./venv/bin/activate.

But typing ./venv/bin/activate and then deactivate is too much work for my lazy programmer head.

So I decided to finally invest 10 minutes to free me from activating and deactivating python's env every time I enter or leave a folder with my standard ./venv folder:

#---------------------------------------------- chpwd pyvenv ---
python_venv() {
  MYVENV=./venv
  # when you cd into a folder that contains $MYVENV
  [[ -d $MYVENV ]] && source $MYVENV/bin/activate > /dev/null 2>&1
  # when you cd into a folder that doesn't
  [[ ! -d $MYVENV ]] && deactivate > /dev/null 2>&1
}
autoload -U add-zsh-hook
add-zsh-hook chpwd python_venv

python_venv

edit: just figured out that deactivating was working because of other stuff installed in my shell. Now it's a bit more agressive but works 100%

edit2: been trying out fish shell. Here it is translated to fish script:

function python_venv --on-variable PWD
    set myvenv ./venv
    if test -d $myvenv
        source $myvenv/bin/activate.fish
    else if type -q deactivate
        deactivate
    end
end

Comments

[Dillon Barnes]

Awesome! This is really useful for me. Do I just put the code in the .zshrc file?

[MoniqueLive]

Yup, that's what I did.

[Dillon Barnes]

Thanks!

[Ali Mehraji]

so what should we do when a parrent directory has venv but child ones dosnt ?
when im in project dir that has venv its okay but when cd to child dir it deactivates the venv

[MoniqueLive]

You’re right. It will deactivate.

[Alan J Bibins]

Thank you so much!! This is exactly what I was looking for :D