Às 20:34 de 22/10/21, Chris Angelico escreveu: > On Sat, Oct 23, 2021 at 6:24 AM Jon Ribbens via Python-list > <python-list@python.org> wrote: >> >> On 2021-10-22, Stefan Ram <r...@zedat.fu-berlin.de> wrote: >>> Paulo da Silva <p_d_a_s_i_l_v_a...@nonetnoaddress.pt> writes: >>>> Why doesn't this work >>>> if (self.ctr:=self.ctr-1)<=0: >>>> while this works >>>> if (ctr:=ctr-1)<=0: >>> >>> assignment_expression ::= [identifier ":="] expression, >>> but the attribute references "self.ctr" is no identifier! >> >> This seems a surprising omission. You'd expect at least 'attributeref' >> and 'subscription' to be allowed, if not the whole of 'target'. > > That's not the primary use-case for assignment expressions, and they > were highly controversial. It is much easier to expand it afterwards > than to restrict it, or to have the feature rejected because people > are scared of some small aspect of it. > > If you want to propose relaxing the restrictions, make your use-case > and attempt to convince people of the value. > Well, I didn't follow the discussion of this new feature, but the reason I can see behind allowing it seems so valid for for ctr:=ctr-1 as for self.ctr:=self.ctr-1. The kind of use is exactly the same. One is for a normal function, the other for a method. IMHO this makes no sense at all. Arguable may be for example LHS ctrs[i], or something like that. But self.ctr ...! Too weird.
Thanks Paulo -- https://mail.python.org/mailman/listinfo/python-list
