CroissantΒΆ
Croissant π₯ is a high-level format building on schema.org for machine learning datasets that combines metadata, resource file descriptions, data structure, and default ML semantics into a single file. It works with existing datasets to make them easier to find, use, and support with tools.
Here, we demonstrate how LaminDB can be used to validate Croissant files:
# pip install lamindb
!lamin init --storage ./test-lamin-croissant
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β’ resetting django module variables
β initialized lamindb: anonymous/test-lamin-croissant
import lamindb as ln
import json
ln.track()
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β connected lamindb: anonymous/test-lamin-croissant
β created Transform('cMpHmaJ2grEh0000'), started new Run('TItcfIxD...') at 2025-09-27 18:23:56 UTC
β notebook imports: lamindb==1.11.3
β’ recommendation: to identify the notebook across renames, pass the uid: ln.track("cMpHmaJ2grEh")
croissant_path, dataset1_path = ln.examples.croissant.mini_immuno()
croissant_path
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PosixPath('mini_immuno.anndata.zarr_metadata.json')
with open(croissant_path) as f:
dictionary = json.load(f)
print(json.dumps(dictionary, indent=2))
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{
"@context": {
"@vocab": "https://schema.org/",
"cr": "https://mlcommons.org/croissant/",
"ml": "http://ml-schema.org/",
"sc": "https://schema.org/",
"dct": "http://purl.org/dc/terms/",
"data": "https://mlcommons.org/croissant/data/",
"rai": "https://mlcommons.org/croissant/rai/",
"format": "https://mlcommons.org/croissant/format/",
"citeAs": "https://mlcommons.org/croissant/citeAs/",
"conformsTo": "https://mlcommons.org/croissant/conformsTo/",
"@language": "en",
"repeated": "https://mlcommons.org/croissant/repeated/",
"field": "https://mlcommons.org/croissant/field/",
"examples": "https://mlcommons.org/croissant/examples/",
"recordSet": "https://mlcommons.org/croissant/recordSet/",
"fileObject": "https://mlcommons.org/croissant/fileObject/",
"fileSet": "https://mlcommons.org/croissant/fileSet/",
"source": "https://mlcommons.org/croissant/source/",
"references": "https://mlcommons.org/croissant/references/",
"key": "https://mlcommons.org/croissant/key/",
"parentField": "https://mlcommons.org/croissant/parentField/",
"isLiveDataset": "https://mlcommons.org/croissant/isLiveDataset/",
"separator": "https://mlcommons.org/croissant/separator/",
"extract": "https://mlcommons.org/croissant/extract/",
"subField": "https://mlcommons.org/croissant/subField/",
"regex": "https://mlcommons.org/croissant/regex/",
"column": "https://mlcommons.org/croissant/column/",
"path": "https://mlcommons.org/croissant/path/",
"fileProperty": "https://mlcommons.org/croissant/fileProperty/",
"md5": "https://mlcommons.org/croissant/md5/",
"jsonPath": "https://mlcommons.org/croissant/jsonPath/",
"transform": "https://mlcommons.org/croissant/transform/",
"replace": "https://mlcommons.org/croissant/replace/",
"dataType": "https://mlcommons.org/croissant/dataType/",
"includes": "https://mlcommons.org/croissant/includes/",
"excludes": "https://mlcommons.org/croissant/excludes/"
},
"@type": "Dataset",
"name": "Mini immuno dataset",
"description": "A few samples from the immunology dataset",
"url": "https://lamin.ai/laminlabs/lamindata/artifact/tCUkRcaEjTjhtozp0000",
"creator": {
"@type": "Person",
"name": "falexwolf"
},
"dateCreated": "2025-07-16",
"cr:projectName": "Mini Immuno Project",
"datePublished": "2025-07-16",
"version": "1.0",
"license": "https://creativecommons.org/licenses/by/4.0/",
"citation": "Please cite this dataset as: mini immuno (2025)",
"encodingFormat": "zarr",
"distribution": [
{
"@type": "cr:FileSet",
"@id": "mini_immuno.anndata.zarr",
"containedIn": {
"@id": "directory"
},
"encodingFormat": "zarr"
}
],
"cr:recordSet": [
{
"@type": "cr:RecordSet",
"@id": "#samples",
"name": "samples",
"description": "my sample"
}
]
}
dataset1_path
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PosixPath('mini_immuno.anndata.zarr')
artifact = ln.integrations.curate_from_croissant(croissant_path)
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! calling anonymously, will miss private instances
! file path mini_immuno.anndata.zarr is not part of a known storage location, will be duplicated to: StorageSettings(root='/home/runner/work/lamin-mlops/lamin-mlops/docs/test-lamin-croissant', uid='pHKvxM48WxeM')
Project label, license, description, version tag, and file paths are automatically extracted from the Croissant file. More metadata can be supported in the future.
artifact.describe()
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Artifact .anndata.zarr Β· AnnData Β· dataset βββ General β βββ key: mini_immuno.anndata.zarr β βββ description: Mini immuno dataset - A few samples from the immunology dataset β βββ uid: mB4RZMxjer85xO5D0000 hash: N4_3ooEU3qkk97bWijn9XA β βββ size: 21.5 KB transform: croissant.ipynb β βββ space: all branch: all β βββ created_by: anonymous created_at: 2025-09-27 18:23:57 β βββ n_files: 95 version: 1.0 β βββ storage path: /home/runner/work/lamin-mlops/lamin-mlops/docs/test-lamin-croissant/mini_immuno.anndata.zarr βββ Labels βββ .projects Project Mini Immuno Project .ulabels ULabel https://creativecommons.org/licenses/byβ¦
ln.finish()
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β finished Run('TItcfIxD') after 2s at 2025-09-27 18:23:58 UTC