Power

Should I install DNF or YUM for a Python installation on Aix v7.2 and what is 3.5 of Python still supported? 

Jim, I'm actually glad to hear someone else asking the question this way: "Should I?". I'm pretty sure that the "official IBM" response is "yes": install dnf to install Open Source python. But I haven't heard many discussions (or pushback against IBM on this position) as to whether this approach is "best" or not. There are some pretty broad-ranging ramifications to this approach. First, this presumes that you must have some means of maintaining a dnf repository (or multiple) that all machines in your enterprise have access to. Second--and this is the "non-starter" from my perspective--is it really a good idea to permit the installation of ANY or ALL of the packages present in the dnf catalog (or repo) on ANY AIX server in my enterprise? I'm thinking "not only no, but __LL NO!". I suppose it might be possible to maintain an austere dnf repository containing ONLY those packages which are absolutely necessary for client applications that rely on these utilities. But it strikes me as a significant additional workload to maintain such a repository. Finally, a casual perusal of anything "dnf" on this community would suggest that dnf for AIX is a "gift that keeps on giving". Maybe that's just because it is in wide use and people only post here when something goes wrong. But it sure does seems to me that dnf is "broken" a lot. So I'm saying "no" to dnf, for now. Client demand may some day force my hand on this issue, but for now I'm sticking with a "everything I need and nothin' I don't" approach to providing specific RPM packages. 

Rant over. You probably want to reconsider python3.5 and go with python3.9.18.0, though. I just saw a Security Bulletin about python3.9 below this level yesterday which caused me to download the fix for the AIX distribution of python3.9.17.0.base included with AIX 7.3.1.2.