Misuse of the "not in" python syntax

[Zhongyue Luo]

There are some lines in the code which uses "if not X is Y"

It should be fixed to "if X is not Y"

ML discussion held at http://lists.openstack.org/pipermail/openstack-dev/2013-January/005243.html

[Maru Newby (maru)]

Can you please clarify the description of this bug? The two statements listed are logically equivalent, and there is no project documentation (say, in HACKING.rst) that requires one or the other.

[Zhongyue Luo (zyluo)]

Maru,

Yes the two statements are logically equivalent.

However in terms of readability, the "is not" keyword is more friendlier to the reader compared to "not X is Y"

I am also planning to write this in HACKING.rst.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/20884

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/20884
Committed: http://github.com/openstack/quantum/commit/4ab676fc4f98f2b67e7b1ae7dbed657d602a95a1
Submitter: Jenkins
Branch: master

commit 4ab676fc4f98f2b67e7b1ae7dbed657d602a95a1
Author: Zhongyue Luo <email address hidden>
Date: Thu Jan 31 16:08:26 2013 +0800

    Fixes 'not in' operator usage

    Fixes bug #1110058

    Change-Id: I45c10097abfb929918925e7befb8ed6c36b1de1c

[Akihiro Motoki (amotoki)]

@zyluo
Could you file another bug to add it to HACKING.rst?

Moreover, it would be better we have a pointer to the discussion on ML in the bug report.

[Zhongyue Luo (zyluo)]

@amotoki: will do.

[Zhongyue Luo (zyluo)]

@amotoki: Oh but mnewby is againt adding this rule to HACKING.rst. However it is already added in the HACKING.rst of oslo, nova, cinder, glance and keystone. Maybe we can talk about it today at the IRC meeting.