Certainly seen a huge rise in Python use in private banking sector where I work. The problem is that we get people who aren't devs writing Python code against source DBs, we once had to fight off a trader who fired up some Python code with 150 simultaneous connections to a prod DB, we quickly had to instigate limitations on DB connections for normal users, something we should have done long ago.

Our company runs training courses on Python, they're not run by devs or even by the IT dept but by one of the members of the key reporting team, a good Python programmer with plenty of experience in financial modelling but zero IT dev experience. Things are changing.

Maybe in trading where information is standardized and in digital form. But for the most part actual financial advisory type banking or investments in private/public companies is still reliant on excel until frameworks for labelled financial information becomes more widely used/implemented in both public and private markets (https://en.wikipedia.org/wiki/XBRL).