This repostory contains a ZSH plugin which automatically activates Python virtual environments when entering their parent directory.

The script create_examples.sh can generate some example directories which also act as test cases. Try doing something like this:

source autovenv.plugin.zsh
./create_examples.sh
cd example-basic/
cd ..

The heart of this plugin is the following table, corresponding to the logic in _autovenv_update.

* The path of the virtual environment discovered from $PWD is compared to the one specified by $VIRTUAL_ENV. If they are dissimilar, the latter is deactivated and the former is activated.

** deactivate is the shell function which the setup script in .venv/bin/activate defines. We use it as an indicator of whether there is an active virtual environment. See this commit if you're curious about why we don't just use $VIRTUAL_ENV.

The rest of the logic should be pretty clear from the source code (as clear as shell script can be, that is).