I would like to install Python on an Apple eMac running OS X 10.5.8.
I downloaded an install package for Python 3.5.4 and it installed just fine. With some help from Google I was able to install pip and pip3.
Unfortunately, I am not able to install any packages, like NumPy. I get a lot of errors when I run pip3. pip3 starts trying to install v1.18.5 of NumPy, bonks out, goes down to a lower subversion, bonks out again, and keeps reducing the subversion until it gives up. I think it has something to do with the lack of modern security certificates. The machine itself is ~20 years old and the OS isn’t much newer.
I asked this question on the 68K MLA forum and a fellow member recommended I use Macports since the target machine is so old. Before I venture into new-to-me territory, I wanted to ask if there is something – anything – else I could try way to make my current installation successful.
I’m a bit novice newbie here, so please forgive me if I am not describing everything properly.
Thanks! 
It’s really hard to install stuff on such an old OS (released in 2007 I just read), at least I don’t know of any shortcuts. For every extra package you will need to figure out what the supported versions are for Python 3.5.4. If it’s just numpy, you could consider looking in the release notes and look for a compatible version. But for every 3d party package you will have to do a similar exercise. So, for installing those extra packages you’d still typically be using pip, not MacPorts or brew, you just need to know the right versions…
Problem may also be that if you try to install something and that has itself certain dependencies (that are not restricted for versions), then those might be installed with incompatible versions…