Patterned field with insupported regex

[unlisted]

I'm trying to generate a Pydantic v2 model and then import it. The OpenAPI spec includes some objects in the schema that have patterned fields with patterns that are unsupported by Pydantic v2. Here's an example of a field from a class generated from that spec

    beneficial_owner_id: Annotated[
        Optional[str],
        Field(
            description='The ID associated to be with the beneficial owner for future requests. If not provided on creation, Canopy will generate this field.',
            example='0x1234',
            pattern='^(?!can_).*$',
        ),

Then import fails when Pydantic tries to create the validator

(venv) morgan@LAPTOP-O1G4SPR0:~/d/lab/python/codegen$ python -c "import model.py"
Traceback (most recent call last):
  File "<string>", line 1, in <module>
  File "/home/morgan/d/lab/python/codegen/model.py", line 4092, in <module>
    class BeneficialOwner(BaseModel):
  File "/home/morgan/d/lab/python/codegen/venv/lib/python3.10/site-packages/pydantic/_internal/_model_construction.py", line 184, in __new__
    complete_model_class(
  File "/home/morgan/d/lab/python/codegen/venv/lib/python3.10/site-packages/pydantic/_internal/_model_construction.py", line 499, in complete_model_class
    cls.__pydantic_validator__ = create_schema_validator(schema, core_config, config_wrapper.plugin_settings)
  File "/home/morgan/d/lab/python/codegen/venv/lib/python3.10/site-packages/pydantic/plugin/_schema_validator.py", line 34, in create_schema_validator
    return SchemaValidator(schema, config)
pydantic_core._pydantic_core.SchemaError: Error building "model" validator:
  SchemaError: Error building "model-fields" validator:
  SchemaError: Field "beneficial_owner_id":
  SchemaError: Error building "default" validator:
  SchemaError: Error building "nullable" validator:
  SchemaError: Error building "str" validator:
  SchemaError: regex parse error:
    ^(?!can_).*$
     ^^^

(venv) morgan@LAPTOP-O1G4SPR0:~/d/lab/python/codegen$ python -c "from importlib.metadata import version; print(version('datamodel_code_generator'))"
0.22.1
(venv) morgan@LAPTOP-O1G4SPR0:~/d/lab/python/codegen$ python -c "from importlib.metadata import version; print(version('pydantic'))"
2.4.2
(venv) morgan@LAPTOP-O1G4SPR0:~/d/lab/python/codegen$ python -c "from importlib.metadata import version; print(version('pydantic_core'))"
2.10.1

Do I just need to strip out the pattern? Is there a command option that can do that? Should this be submitted as an issue, the fact the spec is converted even though some fields are invalid (according to Pydantic v2)?

Here's the command used to generate the models
datamodel-codegen --url https://docs.canopyservicing.com/openapi/645bb7f0ea9f151255ed1f70 --output model.py --output-model-type pydantic_v2.BaseModel --use-annotated

[koxudaxi]

This issue has been fixed in v0.25.7+ - the generator now automatically detects lookaround patterns and adds regex_engine="python-re" to ConfigDict, so please upgrade to resolve this. Thank you!!