I just read this and _think_ I understand it
I gather that the Fedora folk think that using:
#!/usr/bin/python
is good. /usr/bin/python is currently a link to python2 and will, eventually, be changed to /usr/bin/python3. Can anyone confirm this? If so, I'd suggest we change to #!/usr/bin/python.
Fedora installs both 2 and 3 as do many other distros.
It's probably easy enough to change to python3 if the user really wants that. On my system I have 2 scripts: mma (the env default) and mma3 (which uses python3).