Hi Pavel - back in 2014 (!), you suggested supporting python2 and python3 simultaneously: https://debbugs.gnu.org/cgi/bugreport.cgi?bug=17811 Essentially by defining a new "python3" primary to sit alongside "python".
Agreed that this is desirable in general. It's now being discussed in https://debbugs.gnu.org/cgi/bugreport.cgi?bug=71672 via a somewhat different approach. I'd worry about making python3 a new primary, since 3 vs. 2 is not the only distinction needed, as has been discussed. I'm closing this one to reduce duplication in the bugdb, but feel free to reply on 71762 or open a new issue if desired. --thanks, karl.