ISONantic

DEPRECATED: This package has been merged into ison-py. Please use ison_parser.validation instead.

pip install ison-py

# Old (deprecated)
from isonantic import TableModel, Field

# New (recommended)
from ison_parser.validation import TableModel, Field

This package will no longer receive updates. All new features and bug fixes will be made to ison-py.

ISONantic - A Pydantic-like data validation library for ISON format.

Features

• Pydantic-like models for ISON data validation
• Type-safe parsing of LLM structured outputs
• Reference resolution across ISON blocks
• Custom validators and computed fields
• Schema generation for LLM prompts
• Error recovery for malformed LLM outputs

Installation

pip install isonantic

Quick Start

Define Models

from isonantic import TableModel, ObjectModel, Field, Reference

class Team(TableModel):
    __ison_block__ = "table.teams"
    id: int = Field(primary_key=True)
    name: str
    budget: float

class User(TableModel):
    __ison_block__ = "table.users"
    id: int = Field(primary_key=True)
    name: str
    email: str
    team: Reference[Team]  # Reference to Team by ID

Parse ISON Data

from isonantic import ISONDocument, parse_ison

ison_data = """
table.teams
id name budget
1 Engineering 500000
2 Marketing 250000

table.users
id name email team
1 Alice alice@example.com :1
2 Bob bob@example.com :2
"""

# Parse with validation
doc = ISONDocument()
doc.register(Team, User)
doc.parse(ison_data)

# Access typed data
users = doc.get_all(User)
for user in users:
    print(f"{user.name} - Team: {user.team.name}")  # Reference auto-resolved!

Parse LLM Output

from isonantic import parse_llm_output, ParseResult

# LLM may return partial or malformed ISON
llm_response = """
Here's the data you requested:

table.products
id name price
1 Widget 9.99
2 Gadget 19.99

The products are ready.
"""

result: ParseResult = parse_llm_output(llm_response, [Product])
if result.success:
    products = result.data[Product]
else:
    print(f"Errors: {result.errors}")

Schema for Prompts

from isonantic import prompt_for_model

# Generate ISON schema for LLM prompts
prompt = prompt_for_model(User)
print(prompt)
# Output:
# table.users
# id:int name:string email:string team:ref
# <rows>

Model Types

TableModel

For tabular data with multiple rows:

class Product(TableModel):
    __ison_block__ = "table.products"
    id: int = Field(primary_key=True)
    name: str
    price: float

ObjectModel

For single key-value configurations:

class Config(ObjectModel):
    __ison_block__ = "object.config"
    timeout: int = 30
    debug: bool = False
    api_key: str

MetaModel

For metadata blocks:

class DocumentMeta(MetaModel):
    __ison_block__ = "meta.document"
    title: str
    version: str
    created: str

Field Options

from isonantic import Field, Reference, LazyReference

class User(TableModel):
    # Primary key
    id: int = Field(primary_key=True)

    # Required field
    name: str = Field()

    # Optional with default
    active: bool = Field(default=True)

    # Reference to another model
    team: Reference[Team]

    # Lazy reference (resolved on access)
    manager: LazyReference[User] = None

    # Constrained field
    age: int = Field(ge=0, le=150)

    # Pattern validation
    email: str = Field(pattern=r'^[\w.]+@[\w.]+$')

Validators

from isonantic import TableModel, validator, root_validator, computed

class Order(TableModel):
    __ison_block__ = "table.orders"

    id: int = Field(primary_key=True)
    quantity: int
    unit_price: float

    @computed
    def total(self) -> float:
        return self.quantity * self.unit_price

    @validator('quantity')
    def validate_quantity(cls, v):
        if v <= 0:
            raise ValueError('Quantity must be positive')
        return v

    @root_validator
    def validate_order(cls, values):
        if values.get('total', 0) > 10000:
            raise ValueError('Order total exceeds limit')
        return values

Reference Resolution

ISONantic automatically resolves references between blocks:

# ISON data with references
ison = """
table.departments
id name
D1 Engineering
D2 Sales

table.employees
id name dept
E1 Alice :D1
E2 Bob :D2
"""

doc = ISONDocument()
doc.register(Department, Employee)
doc.parse(ison)

emp = doc.get(Employee, "E1")
print(emp.dept.name)  # "Engineering" - auto-resolved!

Error Handling

from isonantic import parse_ison_safe, ValidationError

try:
    result = parse_ison_safe(data, [User, Team])

    if result.has_errors:
        for error in result.errors:
            print(f"Error: {error}")

    # Access valid data even with partial errors
    users = result.data.get(User, [])

except ValidationError as e:
    print(f"Validation failed: {e}")

Use Cases

• LLM Structured Output - Parse and validate AI-generated data
• Configuration Files - Type-safe config loading
• API Responses - Validate ISON API data
• Data Pipelines - Transform and validate ISON streams
• RAG Systems - Parse retrieved ISON documents

Comparison with Pydantic

Test Results

All tests passing:

============================= test session starts =============================
platform win32 -- Python 3.12.7, pytest-8.4.1

tests/test_isonantic.py::TestBasicModels::test_create_simple_model PASSED
tests/test_isonantic.py::TestBasicModels::test_model_with_reference PASSED
tests/test_isonantic.py::TestBasicModels::test_field_constraints PASSED
tests/test_isonantic.py::TestBasicModels::test_string_pattern_validation PASSED
tests/test_isonantic.py::TestBasicModels::test_min_max_length PASSED
tests/test_isonantic.py::TestBasicModels::test_choices_validation PASSED
tests/test_isonantic.py::TestValidators::test_field_validator PASSED
tests/test_isonantic.py::TestValidators::test_root_validator PASSED
tests/test_isonantic.py::TestValidators::test_computed_field PASSED
tests/test_isonantic.py::TestParsing::test_parse_single_model PASSED
tests/test_isonantic.py::TestParsing::test_parse_with_references PASSED
tests/test_isonantic.py::TestParsing::test_parse_safe PASSED
tests/test_isonantic.py::TestParsing::test_parse_null_values PASSED
tests/test_isonantic.py::TestDocument::test_parse_document PASSED
tests/test_isonantic.py::TestDocument::test_reference_resolution PASSED
tests/test_isonantic.py::TestDocument::test_reference_validation PASSED
tests/test_isonantic.py::TestDocument::test_document_serialization PASSED
tests/test_isonantic.py::TestLLMParsing::test_parse_clean_llm_output PASSED
tests/test_isonantic.py::TestLLMParsing::test_parse_llm_with_extra_text PASSED
tests/test_isonantic.py::TestLLMParsing::test_parse_llm_code_block PASSED
tests/test_isonantic.py::TestLLMParsing::test_llm_parse_error PASSED
tests/test_isonantic.py::TestSchemaGeneration::test_generate_model_schema PASSED
tests/test_isonantic.py::TestSchemaGeneration::test_prompt_for_model PASSED
tests/test_isonantic.py::TestSchemaGeneration::test_json_schema_generation PASSED
tests/test_isonantic.py::TestSchemaGeneration::test_json_schema_with_constraints PASSED
tests/test_isonantic.py::TestSchemaGeneration::test_json_schema_with_pattern PASSED
tests/test_isonantic.py::TestSchemaGeneration::test_json_schema_with_choices PASSED
tests/test_isonantic.py::TestSchemaGeneration::test_json_schema_with_reference PASSED
tests/test_isonantic.py::TestSchemaGeneration::test_json_schema_json_output PASSED
tests/test_isonantic.py::TestSchemaGeneration::test_pydantic_v1_compatibility PASSED
tests/test_isonantic.py::TestSerialization::test_model_to_dict PASSED
tests/test_isonantic.py::TestSerialization::test_model_with_reference_to_dict PASSED
tests/test_isonantic.py::TestSerialization::test_model_to_ison_table PASSED
tests/test_isonantic.py::TestSerialization::test_model_copy PASSED
tests/test_isonantic.py::TestEdgeCases::test_empty_ison PASSED
tests/test_isonantic.py::TestEdgeCases::test_missing_required_field PASSED
tests/test_isonantic.py::TestEdgeCases::test_extra_fields_ignored PASSED
tests/test_isonantic.py::TestEdgeCases::test_quoted_strings_with_spaces PASSED
tests/test_isonantic.py::TestEdgeCases::test_special_characters_in_strings PASSED

============================= 39 passed in 0.09s ==============================

Run tests with:

pytest tests/

Links

• Documentation | www.getison.com
• ISON Specification
• GitHub
• ison-py

License

MIT License - see LICENSE for details.