Greg Ewing wrote: > On 23/11/20 7:49 am, Daniel Moisset wrote: > > Look at the following (non-pattern-matching) > > snippet: > > event = datetime.date(x, month=y, day=z) > > > > The only names that are treated as lvalues there are to the left > of an '='. The rules are a lot simpler. > One of the Zen lines says "If it's hard to explain, it's probably > a bad idea." I think the proposed rules for match cases are > objectively harder to explain than those for other expressions, > because they're more complicated.
I don't believe that it is correct that `month` in `month=y` and `day` in `day=z` in the expression `event = datetime.date(x, month=y, day=z)` are lvalues. They are definitely not assignment targets in the same sense that `event` is an assignment target. `month` and `day` are used to bind the arguments `y` and `z` to the `month` and `day` arguments accepted by the `date` constructor. `event` can be accessed and rebound in the scope that invokes `datetime.date`. However, `month` and `day` are only bound to `y` and `z` in the scope of the body of the `datetime.date` constructor and are not accessible in the scope that invokes `datetime.date`. The behaviour is significantly different. _______________________________________________ Python-Dev mailing list -- python-dev@python.org To unsubscribe send an email to python-dev-le...@python.org https://mail.python.org/mailman3/lists/python-dev.python.org/ Message archived at https://mail.python.org/archives/list/python-dev@python.org/message/FDEVMYO3YCFZO3UYTP7D2G3HHKFP7EXQ/ Code of Conduct: http://python.org/psf/codeofconduct/
