On Mon, Jul 23, 2018 at 2:23 AM Nicholas Cole <nicholas.cole@gmail.com> wrote:

One issue for me is that the trivial case is already a one-liner:

if a is None: a = 10

Yes, if you have no indentation and a 1-character name, then it fits on a single line. If you have a longer expression and/or side effects, then it's not a one-liner anymore.

And that leads to a simple question: how many times does this actually
occur in real-world by python code? -- i.e. how many times do I want
to check the value of an existing label, and, finding it is None (and
None specifically), then assign it a value?

What does a scan through the existing core library say?

Please read the PEP before you shoot it down. It answers this _exact_ question.