Automatically activate and deactivate Python virtual envs on change directory

.bashrc

# Include this in your .bashrc:

function activate_virtualenv () {
    [[ -n $VIRTUAL_ENV ]] && deactivate;
    venv=`python3 ~/.find_venv.py .`;
    [[ ! -z "$venv" ]] && . $venv/bin/activate;
    return 0
}

function cd () {
    builtin cd "$@" && activate_virtualenv
}

.find_venv.py

# Save this script as .find_venv.py in your home directory:

import pathlib
import sys


def virtual_env(path):
    """Recursively find the virtual env, if any."""
    path = path.resolve()
    for each_path in [path] + list(path.parents):
        try:
            if virtual_envs := [d for d in each_path.iterdir() if d.is_dir() and (d / 'pyvenv.cfg').exists()]:
               return str(virtual_envs[0])
        except OSError:
            pass
    return ""


if __name__ == "__main__":
   print(virtual_env(pathlib.Path(sys.argv[1])))