xsdata-pydantic

24.5 verified Mon Apr 27 auth: no python

xsdata-pydantic is a plugin for xsdata that generates Pydantic models from XML Schema (XSD) documents. It provides a code generator producing Python classes with Pydantic v1 or v2 support, data binding, and serialization. The current version is 24.5, compatible with Python >=3.8 and xsdata >=22.10. Release cadence is irregular.

pip install xsdata-pydantic

Common errors

error ModuleNotFoundError: No module named 'xsdata_pydantic' ↓

cause The package is not installed or installed under a different name.

fix

Run 'pip install xsdata-pydantic'

error AttributeError: module 'xsdata_pydantic' has no attribute 'PydanticExtension' ↓

cause Using an older version (<24.0) where the extension was named differently or not yet introduced.

fix

Upgrade xsdata-pydantic to version 24.0+: 'pip install --upgrade xsdata-pydantic'

error pydantic.errors.PydanticUserError: Field name "type" shadows a BaseModel attribute; use a different field name ↓

cause XML schema has an element named 'type' which conflicts with Pydantic's built-in type field.

fix

Use xsdata's renaming feature: add '--field-name-policy' or customize the generator to rename conflicting fields.

Warnings

breaking In version 24.x, Pydantic v2 is the default. If you need Pydantic v1, you must explicitly set the extension with PydanticV1Extension. ↓

fix Use 'from xsdata_pydantic import PydanticV1Extension' and pass it as the extension.

gotcha The generated models are dataclasses with Pydantic validation. They cannot be directly used with raw Pydantic BaseModel methods like .model_dump_json(). Use the xsdata XmlSerializer instead. ↓

fix Use XmlSerializer from xsdata to serialize to XML, or convert to dict/list manually.

deprecated Python 3.8 support will be dropped in a future release. Ensure you use Python 3.9+ for new projects. ↓

fix Upgrade to Python 3.9 or later.

Imports

PydanticExtension

wrong

from xsdata.plugins import PydanticExtension

correct

from xsdata_pydantic import PydanticExtension

The plugin is a separate package; importing from xsdata will fail.

Quickstart

Install the plugin, generate Pydantic models using xsdata CLI with the extension, then parse and serialize XML data.

from xsdata_pydantic import PydanticExtension
from xsdata.formats.dataclass.serializers import XmlSerializer
from xsdata.formats.dataclass.parsers import XmlParser

# Generate models from XSD using CLI or code generator
# Example: xsdata my-schema.xsd --package mypackage --extension PydanticExtension

# After generation, use parser and serializer
parser = XmlParser()
serializer = XmlSerializer()