On Wed, Oct 21, 2020, 12:12 AM Chris Angelico

> But I think what you want is for the binding line never to raise, but also not to have any local means to know whether 'bar' is a name after that line. Or whether 'foo' is, for that matter.

Easy: it always is. Whether it has had a value assigned to it is a separate consideration. Consider:

if cond: x = 1

Is x a name after this line? Yes, yes it is. There's nothing spooky happening here.

I have no idea whether 'x' is a name after that line. Neither do you. I mean, in some Platonic abstraction, I guess 'x' is eternally a name and always has been.

But I have no idea whether the next line of:

print(x)

Will raise an exception or print something out. I.e. is it a key in globals() and/or locals()?

I've been stung many times by thinking "x was surely bound" and finding it wasn't. I'm certain you have been too. But I know that conditional blocks have that special property of maybe being executed, maybe not.

So among other things, you are introducing another way to spell a conditional block. Even the ternary expression cannot conditionally bind a name ('while' blocks can, of course; and try/except blocks). This is way too much baggage for something that is far clearer as a plain function.