Dynamically update content of a card, from Python

Hi. Is there a way through appdaemon to run some Python script that will update a card to show either the contents of a text file or some html. But limit it to just the area that card taxes up in the dashboard.

Ideally I want to have a recipe come out, that a user selects from a drop down list and then in another card the method for that recipe?

Any ideas on how I could achive this would be great, I have got a Markdown card to show Html if I paste the HTML directly into the YAML but not so I can listen to an entity change and then update that card?

Many thanks in advance