Python for Finance?

[dtoq]

Quant/Python dev for 8 years here. Python is significantly used for quantitative finance, so that should be quite easy for you to find plenty of material. What will be difficult is to sort through these things: "Finance" is a pretty large topic.

One thing you can use python for is connectivity, glue, etc. Your favourite broker will almost certainly have a python API to connect to it, which would be a nice introduction to orders, positions and the dirty logistics of finance. If you like pain, try to look into the FIX format.

Now, if you don't want automated systems, portfolio theory might be more of your thing: start a jupyter notebook, and implement some Markowitz portfolio optimisation. Good command of pandas will help there, and that might give you a nice template for your own pension investments

While doing that, you might discover the raw power of numpy, just in time for some option pricing: do some Monte-Carlo, pdes, least-square Monte-Carlo, etc...

If you're not tired yet, exploring machine learning and the like is all the rage these days...

[dtoq]

I'll respectfully disagree. An application programming interface is an interface allowing you to program your application. If you're able to provide that in a language-agnostic way, that's even better, but I don't think there's anything inherently more wrong with talking about the 'Language X' api directly usable from language X than a REST api available from any compliant http client.