python

schema2object — Python

JSON Schema Draft-07 is the object class definition.

ObjectTree(data, schema=schema) — if data violates schema, this raises. The schema is the class contract, not a hint. Construction validates. Mutation validates. No exceptions.

Core Semantics

• Construction validates — invalid data cannot produce a valid instance
• Mutation validates — every write is checked before storage
• to_dict() projects — only schema-defined fields serialize out
• Unknown fields are allowed — extra runtime fields exist but are invisible to to_dict()
• Draft-07 is the target — all keywords, 100% of the official test suite

Install

pip install schema2object

Quick Example

from schema2object import ObjectTree

schema = {
    'type': 'object',
    'properties': {
        'name': {'type': 'string'},
        'age': {'type': 'integer', 'minimum': 0, 'x-docs': 'Age in years'},
        'email': {'type': 'string', 'pattern': r'^[^@]+@[^@]+$'}
    },
    'required': ['name']
}

user = ObjectTree({'name': 'Alice'}, schema=schema)

# Dot-access
print(user.name)  # 'Alice'

# Type checking on assignment
user.age = 30        # ✓ OK
user.age = 'thirty'  # ✗ Raises TypeError

# Explicit schema access
print(user.get_schema('age'))       # {'type': 'integer', 'minimum': 0}
print(user.get_extensions('age'))   # {'x-docs': 'Age in years'}

Draft-07 Logic → Methods

data = ObjectTree({...}, schema=schema)
branch = data.one_of()   # oneOf (XOR)
branches = data.any_of() # anyOf (OR)
merged = data.all_of()   # allOf (AND)
filtered = data.project()# properties (SELECT)

API Reference

ObjectTree

Constructor:

ObjectTree(data=None, *, schema=None, **kwargs)

Methods:

• one_of() → ObjectTree — Select unique oneOf branch
• any_of() → List[ObjectTree] — Get all anyOf matches
• all_of() → ObjectTree — Merge allOf schemas
• not_of(schema=None) → bool — Check exclusion
• if_then() → ObjectTree — Conditional branch
• project() → ObjectTree — Filter to schema fields
• contains(schema=None) → bool — Array element check
• to_dict() → dict — Unwrap to native Python
• get_schema(path=None) → dict|Any — Read schema (dot path supported)
• get_extensions(path=None) → dict — Read x-* extensions on schema

Properties:

• is_mapping → bool
• is_sequence → bool
• schema → dict|Any — Root schema as plain dict

ObjectTreeEncoder

JSON encoder for ObjectTree instances:

import json
json.dumps(obj, cls=ObjectTreeEncoder)

Tests

python -m pytest tests/ -q

See Also

• schema2object root