[BUG] Python: string properties with format uuid and regex: "TypeError: expected string or bytes-like object, got 'UUID'"

[cgoetz-inovex]

Bug Report Checklist

• Have you provided a full/minimal spec to reproduce the issue?
• Have you validated the input using an OpenAPI validator?
• 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?
• [Optional] Sponsorship to speed up the bug fix or feature request (example)

Description

An API spec with a property define like:

type: string
format: uuid
pattern: "^[0-9a-f]{8}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{12}$"

generates a field_validator like:

    @field_validator('id')
    def id_validate_regular_expression(cls, value):
        """Validates the regular expression"""
        if value is None:
            return value

        if not re.match(r"^[0-9a-f]{8}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{12}$", value):
            raise ValueError(r"must validate the regular expression /^[0-9a-f]{8}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{12}$/")
        return value

which raises an type error when calling from_json:

foo = FooGet200Response.from_json('{ "id": "B0D54D06-11DC-4493-BF80-E5C98B0535CC" }')
# will raise TypeError: expected string or bytes-like object, got 'UUID'

openapi-generator version

tested against current master, repo with reproduction: https://github.com/cgoetz-inovex/openapi-generator-python-uuid-regex-issue

OpenAPI declaration file content or url

openapi: 3.1.0
info:
  title: Foo
  description: Foo
  version: 0.0.1
paths:
  /foo:
    get:
      responses:
        "200":
          description: foo
          content:
            application/json:
              schema:
                type: object
                properties:
                  id:
                    type: string
                    format: uuid
                    pattern: "^[0-9a-f]{8}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{12}$"

Generation Details

see https://github.com/cgoetz-inovex/openapi-generator-python-uuid-regex-issue/blob/main/build.sh

Steps to reproduce

see https://github.com/cgoetz-inovex/openapi-generator-python-uuid-regex-issue/blob/main/readme.md

Related issues/PRs

issue introduced here: #21740

template with validator:

openapi-generator/modules/openapi-generator/src/main/resources/python/model_generic.mustache

Line 56 in e1513f7

if not re.match(r"{{{.}}}", value{{#vendorExtensions.x-modifiers}} ,re.{{{.}}}{{/vendorExtensions.x-modifiers}}):

issue flagged here by code review bot: https://github.com/OpenAPITools/openapi-generator/pull/23040/changes

Suggest a fix

I'll contribute a PR with a fix, my current plan would be to extend the validator template with sth. like:

if not isinstance(value, str):
  try:
    value = str(value)
  except: # add appropriate error type here
   pass
# continue with existing regex validation

Not a python dev, so I first have to try it out.