Getting newer versions of Python on long term support releases of Linux distributions, such as Ubuntu or CentOS, without interfering with the system Python can be pretty involved. Doing it on multiple instances is even harder. Fortunately, it is possible and quite easy by using snapd.
A Python virtualenv is an isolated directory that serves as the root filesystem (kind of) for an installation of Python. In simpler terms, Python is installed in a non-privileged directory by a regular user. Anything installed for that instance of Python does not affect any other Python instance installed on the system.
This guide will show you how each instance of a Python interpreter differs from others and how to use this to your advantage.
Are you in the same boat as I was only a few weeks ago? That is, does writing a Makefile intimidates you beyond belief? Fear not! Makefiles appear to be insurmountable (and some of the complicated ones really are) but if you start with simple steps, they are really not that difficult.
EdgeRouter Lite is a great device to run at the edge of a home network. It becomes even better when it's running OpenBSD. This guide documents how to setup such a gateway. There are accompanying git repos to somewhat automate the process as well.
pkgsrc is a cross operating system package manager. It supports -- among many others -- NetBSD, Minix, SmartOS, Linux, and macOS. I like it because of this portability. It also has the additional, and I would say the best, benefit of being installed in the home directory and run completely without needing root access. I also like that I don't have to depend on binary packages built by someone else, say Joyent, although there's absolutely nothing wrong with it. Finally, it provides a large number of different packages. I have never encountered a package that I needed but was not available. In short pkgsrc is a portable, featureful, and flexible package manager. What's not to like?
pkgsrc can sometimes be a little behind native package managers, such as MacPorts on macOS, but it catches up quickly. For my use case -- getting access to multiple versions of Python -- it works well enough if I closely follow its trunk branch.
There's generally good and detailed documentation available for pkgsrc but an introductory guide that pulled in some essential starter information was lacking. This guide fills that void by making it easy to get started with pkgsrc and learn about some of its core concepts. Thus, I dubbed it the mini handbook or the missing starter handbook.
EdgeRouter Lite is a great device to run at the edge of a home network. It becomes even better when it's running FreeBSD. This guide documents how to setup such a gateway. There are accompanying git repos to somewhat automate the process as well.
Tips I have learned on how to do things in shell scripts.
Fixtures are a great feature of PyTest but using them can be tricky. I found them to be very useful when all important environment logic resides in them and tests use a consistent interface without regard to how the environment is actually set up.
There are many options to install newer Python on CentOS, including building from source, installing from EPEL, installing from Software Collections (SCL), installing third party rpm package, etc. These all work to some degree of success. I had a different use case and could not find a pre-built rpm package to fit it.
My use case had these restraints:
- Install newer Python alongside the default system version
- Install multiple Python versions simultaneously
- Install the latest release from upstream Python project not just the latest release from a repository (repo)
- Do not build from source unless absolutely necessary