You can get very far with any python on your system, and just the standard library. Don't bother with pipenv or pyenv. Once you have experience solving problems

You can get very far with any python on your system, and just the standard library. Don't bother with pipenv or pyenv. Once you have experience solving problems with the standard library, learn where pip puts things (probably /usr/local/lib/pythonX.Y/site-packages), use "pip freeze" to list current versions of stuff, and keep it tidy. Don't make a big mess, it won't be a mess. One nifty trick is using the (built-in) subprocess modules to exec some other tool, like rsync or ssh. I recently had sufficient motivation to remove a dependency on the "awscli" package from my deploy system, and implemented an aws api request signing function in about 50 lines of python3.5 using only the standard library. (For bootstrap convenience, my deploy system depends only python3.5 and some standard cli utilities.) For some non-trivial web services, I use tornado. Running under python3, it depends on nothing else, and can take you very far. (Running under python2.7 it has 4 small dependencies.)