Re: why python ?
I can not see what python3 does that perl does not do. I cannot not see what python3 does that python2 does not do. I can see it is popular. But can someone explain why it is popular?. What was added over time that made a break necessary, What are its direct competitors?
In my opinion, Python became popular because it was easy to copy and paste from others code. Which made it easier for "newbies" to program.
Case in point. Back in the turn of the millennium (2000 or so), I wanted to learn to code on Linux. I was still at school and could not afford windows compilers. I could not get my head around C, so I looked at the two main options at the time. Perl was the established player, and this upstart called "Python" had just reached version 2.0.
Logically I went with perl, as it was the most popular, and tried to cobble stuff together the only way I knew, by copy pasting other code I found online, and trying to understand how it worked. Problem is, it just would not work, I would get syntax errors, or other errors, or it just would give incorrect results. I would look for "how to do $x" online and get 20 different ways of doing it, it was overwhelming, and I eventually gave up and tried Python.
Python was different, there is "only one way to do it", which meant I could copy/paste code from different projects and it would work, I could search "how to do $x" and get one overwhelmingly "correct" answer, which worked, and once I understood what a piece of code did, when I read other peoples code I could understand what they were doing.
Python is what got me deep into programming, and indeed I do believe this was one of the reasons many "educational" projects for young children seem to start with Python (or Python-like) programming languages. It is literally the "Basic" of Linux. Nowadays you can code up a python program to do what you want just by copy/pasting from stackoverflow (not that I would recommend it for anything serious, but for newbies it is useful)
Now, 20 years later, I still code in Python, but less and less scripting. The flexibility and string mangling of perl beats python hands down, while for performance I prefer C. Python sits in an interesting niche, I guess roughly where Java does, as kind of "middleware", and also it has some very good libraries for statistical analysis (the "jupyter" notebooks with numpy, pyplot and stats libraries has no equal for the price).
As for the changes between 2 and 3, the only one I was ok with was the conversion of "print" from a statement to a function, beyond that the changes either made no difference to me, or made my life harder, so meh.