[BUG][PYTHON] should only allow timezone-aware datetime

[robertschweizer]

Bug Report Checklist

• Have you provided a full/minimal spec to reproduce the issue?
• Have you validated the input using an OpenAPI validator (example)?
• [] Have you tested with the latest master to confirm the issue still exists?
• Have you searched for related issues/PRs?
• What's the actual output vs expected output?
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Description

As described in OAI/OpenAPI-Specification#1498 (comment), OpenAPI date-time strings must contain time-zone information.

In the Python client generator, the Pydantic fields are annotated with datetime, which allows timezone-naive objects to be passed. When serialized to strings, these do not contain time-zone information like a trailing Z or +00:00. This violates the OpenAPI spec.

openapi-generator version

7.7.0

OpenAPI declaration file content or url

Generation Details

Steps to reproduce

Related issues/PRs

Suggest a fix

I would change the type annotations for date-time format string to pydantic.types.AwareDatetime, to require the time-zone information that the OpenAPI spec asks for when objects are constructed in Python.

This can be a breaking change to users using lenient REST APIs with the generated client. It might also be annoying if server responses contain "incorrect" timezone-naive timestamps and client-side validation fails.

Looking forward to feedback on how this should be best handled, to correctly represent the OpenAPI spec but not be annoying to users.