Message 341183 - Python tracker

Message341183

Author	serhiy.storchaka
Recipients	georg.brandl, gvanrossum, serhiy.storchaka, wim.glenn
Date	2019-05-01.09:23:09
SpamBayes Score	-1.0
Marked as misclassified	Yes
Message-id	<1556702590.11.0.000567590970172.issue36761@roundup.psfhosted.org>
In-reply-to

Content
For the second case, you can use a, L[::2] = "abc" For the first case this does not work, because an assignment can have only one starred expression. Making the first case to work as you expected is breaking change. Currently L[:], rest = 'abcdef' sets L to ['a'] and rest to ['b', 'c', 'd', 'e', 'f']. Consistent implementing of your idea would set L to ['a', 'b', 'c'] and rest to ['d', 'e', 'f'] (because len(L[:]) == 3 before assignment). What is your use case? Why do you need such syntax?

Content

For the second case, you can use

a, *L[::2] = "abc"

For the first case this does not work, because an assignment can have only one starred expression.

Making the first case to work as you expected is breaking change. Currently

L[:], *rest = 'abcdef'

sets L to ['a'] and rest to ['b', 'c', 'd', 'e', 'f']. Consistent implementing of your idea would set L to ['a', 'b', 'c'] and rest to ['d', 'e', 'f'] (because len(L[:]) == 3 before assignment).

What is your use case? Why do you need such syntax?

History
Date	User	Action	Args
2019-05-01 09:23:10	serhiy.storchaka	set	recipients: + serhiy.storchaka, gvanrossum, georg.brandl, wim.glenn
2019-05-01 09:23:10	serhiy.storchaka	set	messageid: <1556702590.11.0.000567590970172.issue36761@roundup.psfhosted.org>
2019-05-01 09:23:10	serhiy.storchaka	link	issue36761 messages
2019-05-01 09:23:09	serhiy.storchaka	create