Extended Data

Extended Data is a Python package family for moving structured values across clear boundaries: parsing input, normalizing and transforming it, preserving ergonomic container behavior, and exporting a plain built-in value when it is time to write or hand data to another library.

Start with the documentation site, especially the Getting Started and Package Surface guides.

Install and choose a layer

pip install extended-data

Most application code needs only these three choices:

1. Use extended_data.primitives for a single deterministic conversion, serialization operation, transform, or redaction step.
2. Use ExtendedData(value) at an uncertain data boundary. It returns the right extended shape (ExtendedDict, ExtendedList, ExtendedString, and so on) while retaining normal Python collection behavior.
3. Use DataFile or DataWorkflow when reading, merging, transforming, or writing a structured artifact is the actual unit of work.

from extended_data import DataWorkflow, ExtendedData
from extended_data.primitives import decode_json, encode_yaml

incoming = decode_json('{"service": {"name": "api"}}')
config = ExtendedData(incoming).merge({"replicas": 2})

result = (
    DataWorkflow.from_value(config)
    .transform("unhump")
    .result()
)

assert result.as_extended()["service"]["name"] == "api"
assert "replicas: 2" in encode_yaml(result.as_builtin())

ExtendedData promotes nested values as they enter or mutate containers. Use as_builtin() (or to_builtin()) at an explicit export boundary when an API, serializer, or third-party library needs ordinary Python dict, list, str, and scalar values.

Consumers that generate or operate code

Automated and agentic consumers should use the same public contract as human callers: import pure functions from extended_data.primitives, promote unknown payloads with ExtendedData, and lower values only at explicit boundaries. The agentic consumer guide sets out the safe integration rules, test plugin, and package ownership limits.

Packages

Distribution	Package path	Purpose
extended-data	packages/extended-data	Runtime data primitives, containers, IO, workflows, inputs, logging, docs, and CLI
pytest-extended-data	packages/pytest-extended-data	Reusable pytest fixtures and assertion helpers for Extended Data consumers

The workspace root is not a published Python distribution. Install a package, not the repository root, in downstream applications.

Common Commands

uv sync --all-packages --all-extras --dev
tox -e lint,typecheck,audit,py311,py312,py313,py314,examples,docs,build
pnpm docs:validate

The Sourcey documentation source lives in docs/ and deploys to https://extended-data.dev. It is independently locked from the Python uv workspace so documentation builds remain deterministic.