STAC extension for generic metadata
This module is a helper to build STAC extensions carrying metadata defined with pydantic models.
Example
Simple example in 4 steps.
Step 1: metadata model
We define a simple metadata model.
import pydantic
from typing import List
class ModelExample(pydantic.BaseModel):
name: str
authors: List[str]
version: strStep 2: create the extension class
We create a stac extension based on this metadata model using the
create_extension_cls() helper.
from stac_extension_genmeta import create_extension_cls
MyExtension = create_extension_cls(
model_cls=ModelExample,
schema_uri="https://example.com/blabla/v1.0.0/schema.json"
)Step 3: instantiate metadata
Let's create some metadata with our metadata model class.
# Create metadata
ext_md = ModelExample(
name="test",
authors=["michel", "denis"],
version="alpha"
)Step 4: apply the extension with the metadata
We can finally apply the extension to STAC items or assets.
STAC Item:
# Apply extension to STAC item
item = ... # some `pystac.Item`
processing_ext = MyExtension.ext(item, add_if_missing=True)
processing_ext.apply(ext_md)STAC Asset:
# Apply extension to STAC asset
asset = ... # some `pystac.Asset`
processing_ext = MyExtension.ext(asset, add_if_missing=True)
processing_ext.apply(ext_md)We can read STAC objects and retrieve the metadata carried by the extension. For instance, with STAC item:
item = ...
MyExtension(item).authors # ["michel", "denis"]