[python] centralize the Python constraint rules

[Mattias-Sehlstedt]

Centralize the handling of applying constraints to different OAS types to remove duplicates (e.g., the current String and Binary logic is the exact same). This also makes it easier to reuse them, for example when creating types that are purely tied to the constraints coming from OAS and not those that may be relevant for different internal Python validators (e.g., Pydantic).

This could also be helpful for the case where you might want to represent constraints differently for different contexts, for example this PR where queries has to be handled differently with how constraints are constructed.

PR checklist

• Read the contribution guidelines.
• Run the following to build the project and update samples:

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

  (For Windows users, please run the script in WSL)
  Commit all changed files.
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• If your PR is targeting a particular programming language, @mention the technical committee members, so they are more likely to review the pull request.

Python technical committee — @cbornet @tomplus @krjakbrjak @fa0311 @multani (@krjakbrjak as the python-fastapi generator author).

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Summary by cubic

Centralized how OAS constraints are applied in the Python generator to remove duplicated logic and keep behavior consistent across types. This simplifies future changes and enables context-specific constraint handling.

• Refactors
  • Added ConstraintApplier and ConstraintType (incl. ROUNDED_NUMBER) to standardize length and numeric rules.
  • Replaced inline constraint code for arrays, strings, binaries, numbers, ints, and decimals in AbstractPythonCodegen; removed PydanticType.applyConstraints and centralized comparison constants.
  • Kept semantics unchanged: inclusive/exclusive bounds, ceil/floor for integer limits, and multiple_of only for non-rounded numeric types.

^{Written for commit dd8d9e7. Summary will update on new commits.}

[cubic-dev-ai]

No issues found across 1 file

_{Re-trigger cubic}