Solution 1:

The Firebase CLI does not support deploying functions written in python.

You can certainly write Cloud Firestore triggers in python and deploy them with gcloud.

One thing you might not be aware of: the underlying Cloud Functions product is the same no matter how you deploy your functions. Firebase just adds tools and APIs on top of the existing Google Cloud Functions infrastructure. There is really no such thing as a "Firebase Cloud Function". There is just Cloud Functions, and you have options about how you can write and deploy them, either using gcloud, or the Firebase CLI.