Hi Jeff,
Thanks so much for jumping in to help. Very much appreciate it, and apologise for the snarkiness that's sneaking in there.
I've been trying to follow the documentation you are pointing to, which seems to be mirrored or repeated on numerous pages around the web, but it seems that there are multiple dependencies that I'm guessing used to be reliable that have been depreciated over time, and Mac OS has also changed quite a bit. Apple's developers seem to be messing with sandboxing and other vain, seemingly unorganised and random attempts at thwarting any potential security vulnerabilities that make things that worked fine in BSD and Linux and therefore could be relied upon to also work in Mac OS, no longer work. All this combined makes getting something like this to work really hard for someone like me.
Apple's SIP, for example, make any directory under /Library/ read-write only by the System unless you shutdown the computer, restart in System Restore mode, disable SIP, restart, make the change, then do it again to re-enable it. So I can't change /Library/Python/2.7/site-packages/ without doing this.
em