On Thu, May 28, 2020 at 10:42 AM Rob Cliffe <rob.cli...@btinternet.com> wrote: > > > > On 26/05/2020 20:03, Chris Angelico wrote: > > On Wed, May 27, 2020 at 2:51 AM Steven D'Aprano <st...@pearwood.info> wrote: > >> But doing otherwise, having Undef be *not an object* but a kinda ghost > >> in the interpreter, is a huge language change and I doubt it would be > >> worth it. > >> > > But is it a huge change? I thought so too, until Greg suggested a > > quite plausible option: leave the local unbound. There'd be two > > changes needed, and one of them could have other value. The semantics > > would be exactly the same as any other unbound local. > > > > def foo(): > > if False: x = 0 > > # what is x now? > > > > There is no *value* in x, yet x has a state. > > [snip] > Sorry, I don't think it does. It's not in locals(), it doesn't exist > anywhere in memory. > It might be created later in foo(), but it would then have a value.
It is in the state of being unbound, and you can prove this by attempting to print it out. >>> foo() Traceback (most recent call last): File "<stdin>", line 1, in <module> File "<stdin>", line 3, in foo UnboundLocalError: local variable 'x' referenced before assignment This is NOT the same as if the assignment hadn't been in the code (which would have gone looking for a global or builtin x). So yes, it does have a state. ChrisA _______________________________________________ Python-ideas mailing list -- python-ideas@python.org To unsubscribe send an email to python-ideas-le...@python.org https://mail.python.org/mailman3/lists/python-ideas.python.org/ Message archived at https://mail.python.org/archives/list/python-ideas@python.org/message/CN3OPIQO4FOIDUADC7TW6RKBY57UKD6U/ Code of Conduct: http://python.org/psf/codeofconduct/
