Common Issues

Pydantic has a compatibility layer to work with dataclasses but there are some known issues.

Nested Classes

If you get value errors or forward res errors, try to generate your models with the flag –unnest-classes. This will move all nested classes to the root level.

xsdata SOURCE --unnest-classes --output pydantic

There are still some issues with self referencing types, check issue on github.

Missing Validators

This plugin will register all the custom validators for the xsdata builtin types like XmlDuration or XmlDate but it’s important to load the plugin before using the models, otherwise you will get an error like this

RuntimeError: no validator found for <class 'xsdata.models.datatype.XmlDuration'>, see `arbitrary_types_allowed` in Config

Loading a serializer or parser is enough for the hook to run.

from pydantic.dataclasses import dataclass
from xsdata.models.datatype import XmlDuration
# import serializer to trigger the xsdata hook to register the validators
from xsdata_pydantic.bindings import XmlSerializer

@dataclass
class DurationRangeMatcherType:
    begin: XmlDuration

print(DurationRangeMatcherType(begin=XmlDuration("PT3S")))