On 23/10/2021 08.34, Chris Angelico wrote: > 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.
ie neither can one use subscripted elements, eg list-elements, as the LHS of an assignment expression. -- Regards, =dn -- https://mail.python.org/mailman/listinfo/python-list
