No Python background is assumed. Indeed, for completeness I give Python language essentials and then move to object-oriented and functional programming (OOP, FP). This is all useful when delving into the (many) useful numerical libraries and after that we design PDE, MC etc. solvers on top of these libraries + OOP/FP extendible design.
The course is hands-on, step-by-step with exercises + mini-project. I am your personal coach essentially The access is forever and you can finish it when it fits in with your plans.
For those who want to know the style, please see this (BTW am in the process of FAQ).
Something like blockchain plays more into your strengths as a CS major and there are several initiatives in trading desks around this theme now, or machine learning engineer (Linear Algebra would be very helpful here). Something quanti I think even one year of prep time will still not get you very far in comparison to math/physics majors. Or Computational finance, where the book by Hull I mentioned above would be sufficient to get started with usually.