Use walrus operator, removing Python 3.7 support

[Safihre]

I would like to start using the new walrus operator that was introduced in Python 3.8.
This would break Python 3.7 support for the next major SABnzbd release.
The official EOL for Python 3.7 is in a few months, so doesn't seem like a big problem?
I also saw that Ubuntu uses Python 3.8 in 20.04 LTS so we are good there.
Anything I'm overlooking here?

[thezoggy]

Hopefully in this docker relevant world we won't be held back by nas with outdated python... But jcfp for example hacks back in py3.6 support for his ppa. So he might be the best sounding board on why not to do it.

[sanderjo]

But jcfp for example hacks back in py3.6 support for his ppa.

Possibly because:

Ubuntu 18.04 is still supported until April 30, 2023 (so 4 more months)
Ubuntu 18.04 has Python3.6

[sanderjo]

About walrus operator:

>>> a=5
>>> if (b:=a+100) > 10: print(b)
... 
105
>>> 

Ah, so finally the C assignment + value in Python? Good.

And "walrus" because of the long teeth in ":=" ?

[jcfp]

jcfp for example hacks back in py3.6 support for his ppa. So he might be the best sounding board on why not to do it.

Don't let that get in the way of progress. The end of the distro's support windows for those old OS releases is approaching fast anyway; any remaining users will just have to enjoy sab 3.7.1 until they finally decide to update.

[Safihre]

Thanks for the input 👍 will go ahead with the changes.