Do not inherit from built-in "dict"

[Rodolfo Alonso]

agent.linux.dhcp.DictModel inherits from built-in "dict" type. This is not recommended because some type methods are implemented not in Python but in C [1][2] and should not be overridden. Subclassing the built-in types directly, will yield non-obvious errors that are hard to debug, and identify at first glance [3].

[1] http://www.kr41.net/2016/03-23-dont_inherit_python_builtin_dict_type.html
[2] https://treyhunner.com/2019/04/why-you-shouldnt-inherit-from-list-and-dict-in-python/
[3] https://medium.com/bynder-tech/using-collections-in-python-36129737b5a1

[Lajos Katona (lajos-katona)]

I set it low as this is not a user facing issue, but of course important to make the code base more robust.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.opendev.org/691874

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.opendev.org/691874
Committed: https://git.openstack.org/cgit/openstack/neutron/commit/?id=4b3baeb15a8015e8ed9075e465cf97800189eef2
Submitter: Zuul
Branch: master

commit 4b3baeb15a8015e8ed9075e465cf97800189eef2
Author: Rodolfo Alonso Hernandez <email address hidden>
Date: Fri Oct 25 17:00:43 2019 +0000

    Do not inherit from built-in "dict"

    This is not recommended because some type methods are implemented not
    in Python but in C [1][2] and should not be overridden. Subclassing
    the built-in types directly, will yield non-obvious errors that are
    hard to debug, and identify at first glance [3].

    [1] http://www.kr41.net/2016/03-23-dont_inherit_python_builtin_dict_type.html
    [2] https://treyhunner.com/2019/04/why-you-shouldnt-inherit-from-list-and-dict-in-python/
    [3] https://medium.com/bynder-tech/using-collections-in-python-36129737b5a1

    Closes-Bug: #1849980

    Change-Id: I08c712ff1b093370cda2ce66b93e2a0709094fe1

[OpenStack Infra (hudson-openstack)]

This issue was fixed in the openstack/neutron 16.0.0.0b1 development milestone.