Thanks for your suggestion @jdlong
I am not from programming background at all. So I don't understand these things much. My primary reason for learning R Instead of python was that it worked much like ms excel. Which was easier for me.
Now I like programming and want to learn it from scratch. You could be right I might never need a highly scaleable application. Yet I work in data domain so if there are more than 10 users trying to get a million rows each to me speed matters there. And we are just talking about 10 users. I know I could be wrong but I had issues in shiny app for speed and I had to hire people to fix it. I just could not do it. I don't want same thing to happen with python.
I could be overly thinking about it but I can write logic I can not re write codes for speed...
Thanks anyways for your suggestion I would keep that in mind that python has risen to world 4th most popular language for a reason.