I'm a Python programmer who's interested in learning a bit of R. I'm still considering what exactly to pick up as a secondary language with R and Rust as my current considerations.
What I basically want to ask is what exactly is R good for? I've heard alot of things about Data Science in R. But I think Python is also used alot in Data Science. So is there any advantage of R over Python?
Assuming I go ahead with R, I'm curious as to what are the R equivalents to libraries like PyQt5 for GUI development. Something modern and new I mean. Something like JavaFX is also good. I've had experience with both.
It's really hard to tell if this is a sincere question. You could always read the Wikipedia page for the R Language if you want to know a little bit about R.
Now, while you can, of course, learn a language for any number of reasons, the best is because you have a reason to. With regards to R, it doesn't sound like you do.
Instead of asking "what is this language good for?" You should ask yourself what you want to do, then find the language that makes that task as easy as possible. Because, at the end of the day, pretty much anything you can do in python, you can do in R, C++, JavaScript, Lisp, Haskell, FORTRAN, COBOL, x86 Assembly, Julia, Visual Basic, or any other Turing complete language (if you're clever and patient enough), and vice versa. It's just that some languages make some jobs easier than others.
Strange to be hesitating between R and Rust: R is a high-level language giving tools to work easily with large amounts of data (interactively playing with it the data is a big part), Rust is a low-level, compiled language designed to be very fast.
R is similar to Python with numpy + pandas + scipy + scikit-learn, so if you work a lot with data most things are about as easy with either R or Python, some things are easier in one or the other (and some are much harder with one or the other).
The use of R is typically centered on data, so modern interfaces are mostly Shiny web-based interfaces, I don't think there is any significant effort in GUI-building from R.