python-pydantic-v1: Keep trailing commas for enum validation tuples

[chiragjn]

It can happen that sometimes a enum just has a single member

This can result in a pydantic validator that can be incorrect
E.g.

class TestClass(BaseModel):
    type: StrictStr = Field(...)  # Say this can only take a single value like "test" 

    @validator('type')
    def type_validate_enum(cls, value):
        if value not in ("test"):
            raise ValueError(...)

If I do some substring of "test", e.g. TestClass(type="tes") this validation will not fail

Then trailing , in this case is required

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[wing328]

thanks for the PR

can you please add a test schema (enum with a single item) in modules/openapi-generator/src/test/resources/3_0/python/petstore-with-fake-endpoints-models-for-testing.yaml ?

[chiragjn]

Tagging @multani for early feedback. Will work on adding small tests

[chiragjn]

Updated samples and added a test

[chiragjn]

Tagging other members of Python committee
@cbornet @tomplus @krjakbrjak @fa0311

[multani]

@chiragjn did you consider replacing the tuples by lists instead?

Semantically, I think it would be more "correct", and syntax-wise it would also prevent this kind of problem.

[chiragjn]

Hmm, sure I don't mind doing that
Thought tuples are faster to allocate hence didn't change
Let me know

[multani]

I'm not sure if that makes such a difference ; if this was a performance problem too, they should be created only once anyway as they are all constants in the end.

We can merge this as it is though.

[multani]

lgtm

@wing328 any preference between tuples and lists? Lists would have prevented this bug in the first place, at the expense of a slight performance penalty.

[wing328]

to me, this is more like an edge case so my take is to use tuple instead.