create_model support generics model

[hot123s]

Change Summary

create_model support generics model

Related issue number

fix #3945

Checklist

• Unit tests for the changes exist
• Tests pass on CI and coverage remains at 100%
• Documentation reflects the changes where applicable
• changes/<pull request or issue id>-<github username>.md file added describing change
  (see changes/README.md for details)
• My PR is ready to review, please add a comment including the phrase "please review" to assign reviewers

[hot123s]

please review

[samuelcolvin]

LGTM, but I wonder if this could have any unintended side effects?

@PrettyWood @hramezani?

[hramezani]

but I wonder if this could have any unintended side effects?

I am not sure. but we need a rebase here to properly handle __cls_kwargs__ and kwds

please update

[hot123s]

I try to extract code from types.new_class to avoid using lambda function

this is source code in python3.8 official library

def new_class(name, bases=(), kwds=None, exec_body=None):
    resolved_bases = resolve_bases(bases)
    meta, ns, kwds = prepare_class(name, resolved_bases, kwds)
    if exec_body is not None:
        exec_body(ns)
    if resolved_bases is not bases:
        ns['__orig_bases__'] = bases
    return meta(name, resolved_bases, ns, **kwds)

I'm alse not sure types.new_class could have any unintended side effects in this project.But this is a official function to create new class, and maybe this is good alternative for type。

@samuelcolvin @hramezani

[hramezani]

Thanks @hot123s for the explanations.

Please consider you need to rebase your patch first.

[PrettyWood]

LGTM! IMO it's ok to add this in v1.10

[hot123s]

@hramezani I have rebased my branch, and compatible with __cls_kwargs__, and add corresponding test case.Please review it.

[hramezani]

Thanks @hot123s 👍

[samuelcolvin]

otherwise LGTM.

[samuelcolvin]

Thanks so much.

[samuelcolvin]

See #4432 related workaround which I think is required due to this PR.