CoverageJSON Pydantic

This repository contains the coveragejson-pydantic Python package. It provides Pydantic models for CoverageJSON. This can, for example, be used to develop an API using FastAPI serving or receiving CoverageJSON.

Install

pip install covjson-pydantic

Or you can install directly from source:

pip install git+https://github.com/KNMI/covjson-pydantic.git

Usage

from datetime import datetime, timezone
from pydantic import AwareDatetime
from covjson_pydantic.coverage import Coverage
from covjson_pydantic.domain import Domain, Axes, ValuesAxis, DomainType
from covjson_pydantic.ndarray import NdArray

c = Coverage(
    domain=Domain(
        domainType=DomainType.point_series,
        axes=Axes(
            x=ValuesAxis[float](values=[1.23]),
            y=ValuesAxis[float](values=[4.56]),
            t=ValuesAxis[AwareDatetime](values=[datetime.now(tz=timezone.utc)])
        )
    ),
    ranges={
        "temperature": NdArray(axisNames=["x", "y", "t"], shape=[1, 1, 1], values=[42.0])
    }
)

print(c.model_dump_json(exclude_none=True, indent=4))

Will print

{
    "type": "Coverage",
    "domain": {
        "type": "Domain",
        "domainType": "PointSeries",
        "axes": {
            "x": {
                "values": [
                    1.23
                ]
            },
            "y": {
                "values": [
                    4.56
                ]
            },
            "t": {
                "values": [
                    "2023-09-14T11:54:02.151493Z"
                ]
            }
        }
    },
    "ranges": {
        "temperature": {
            "type": "NdArray",
            "dataType": "float",
            "axisNames": [
                "x",
                "y",
                "t"
            ],
            "shape": [
                1,
                1,
                1
            ],
            "values": [
                42.0
            ]
        }
    }
}

Contributing

Make an editable installation from within the repository root

pip install -e '.[test]'

Running tests

pytest tests/

Linting and typing

Linting and typing (mypy) is done using pre-commit hooks.

pip install pre-commit
pre-commit install
pre-commit run

Related packages

• edr-pydantic - Pydantic data models for the Environmental Data Retrieval (EDR) API
• geojson-pydantic - Pydantic data models for the GeoJSON spec

Real world usage

This library is used to build an OGC Environmental Data Retrieval (EDR) API, serving automatic weather data station data from The Royal Netherlands Meteorological Institute (KNMI). See the KNMI Data Platform EDR API.

TODOs

Help is wanted in the following areas to fully implement the CovJSON spec:

• The polygon based domain types are not supported.
• The Trajectory and Section domain type are not supported.
• The NdArray only supports float data.
• Not all requirements in the spec relating different fields are implemented.

License

Apache License, Version 2.0