Completely different use cases. I'd bet a hundred that you didn't do any research before asking this question.
Python is for three kinds of people:
-Those who can program but want a quick prototyping language
-Those who know how servers work and want a new web developing environment
-Those who cannot program but need a language that they can do analysis or grunt work with (ie. data analysts, scientists, engineers, etc.)
Outside of those sorts of people, Python has no real use-case. Everything it can do it done better in almost any other language. After prototyping, people rewrite their code in C++, C#, Go, whatever. For larger data analysis, R, MatLab, functional programming languages or even FORTRAN will reign supreme since they're so fast at doing exactly what they do. For web devs, that's just up to preference, since PHP, R/R, and all sorts of other backends exist that do the exact same job.
As for C++, it's well-rounded, relatively safe in comparison to C, but also pretty difficult to pick up as a first language because of all the nuance and general differences that it has with other languages. Also, since it only runs natively, you'll also need to learn how a compiler works (or at least how to compile your code) instead of just plugging it into an interpreter like with Python.
Python is used much for data analysis. IT HAS TONS OF USECASES