Why is Python so hard to maintain

[metulburr]

The only reason you should "need" older versions is because 1) your system requires it (AKA older linux distros use python2.x) and 2) if your using a program that didnt update their code requiring you to have multiple versions.

Regarding #2 i would consider it apart of the programmers fault for not building an executable with the required python version. They should have built it in mind of computer-illiterate folks use their programs. However it is common practice for python programmers to know how to use multiple versions of python, and invke them with whatever they use to type the code (IDE or editor). If your the first i would just aks the programmer

Switching between versions is only as hard as you make it. For me its as simple as invoking the correct python interpreter by modifying the the number given in the terminal

metulburr@ubuntu:~$ python2
Python 2.7.12 (default, Nov 12 2018, 14:36:49) 
[GCC 5.4.0 20160609] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> exit()
metulburr@ubuntu:~$ python3
Python 3.6.1 (default, Jun  8 2017, 06:36:16) 
[GCC 5.4.0 20160609] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> exit()
metulburr@ubuntu:~$ python3.7
Python 3.7.3 (default, Mar 26 2019, 01:59:45) 
[GCC 5.4.0 20160609] on linux
Type "help", "copyright", "credits" or "license" for more information.

All languages evolve. Its not just Python. Java 11 and 12. C++98, C++11 and c++14. The only major incompatibility is in the differences between python3.x and python2.x. And that was to fix a lot of issues. The change happened over a decade ago at this point. 2.x is considered obsolete now.