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.
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