Python: Correctly serialize enum with its value (#18327)

[BaptisteSaves]

Fixes #18327

Add a serialization case when it is an enum to use its value and not its name.

PR checklist

• Read the contribution guidelines.
• Pull Request title clearly describes the work in the pull request and Pull Request description provides details about how to validate the work. Missing information here may result in delayed response from the community.
• Run the following to build the project and update samples:

  ./mvnw clean package 
  ./bin/generate-samples.sh ./bin/configs/*.yaml
  ./bin/utils/export_docs_generators.sh
  

  (For Windows users, please run the script in Git BASH)
  Commit all changed files.
  This is important, as CI jobs will verify all generator outputs of your HEAD commit as it would merge with master.
  These must match the expectations made by your contribution.
  You may regenerate an individual generator by passing the relevant config(s) as an argument to the script, for example ./bin/generate-samples.sh bin/configs/java*.
  IMPORTANT: Do NOT purge/delete any folders/files (e.g. tests) when regenerating the samples as manually written tests may be removed.
• File the PR against the correct branch: master (upcoming 7.1.0 minor release - breaking changes with fallbacks), 8.0.x (breaking changes without fallbacks)
• If your PR is targeting a particular programming language, @mention the technical committee members, so they are more likely to review the pull request.

cc @cbornet @tomplus @krjakbrjak @fa0311 @multani

[BaptisteSaves]

Is there any way to add a test that would run the generated Python code ? (IE a pytest)

[multani]

@BaptisteSaves you can add a new test, for instance in this folder: https://github.com/OpenAPITools/openapi-generator/tree/master/samples/openapi3/client/petstore/python/tests

[wing328]

here is an example on how to add a test: https://github.com/OpenAPITools/openapi-generator/pull/18272/files#diff-865b48c6f08b84b32f8fa35cc3bf6c755b919e5f05c4c2bb157ea9ea589bba0aR622

[BaptisteSaves]

@wing328 @multani I added a test ensuring the param is now right.

I have a red build on samples generation but locally ./bin/generate-samples.sh does not produce any changes. Do you know how to fix it ?

[wing328]

please ignore https://github.com/OpenAPITools/openapi-generator/actions/runs/8614615152/job/23608628515?pr=18328 for the time being.

i'll take a look

update: fixed in the latest master

[wing328]

would it be possible to write a unit test for sanitize_for_serialization with enum ?

[wing328]

e.g. https://github.com/OpenAPITools/openapi-generator/blob/master/samples/openapi3/client/petstore/python/tests/test_api_client.py#L128

[BaptisteSaves]

Done

[fa0311]

LGTM! thanks!