CVCDocDB

CVCDocDB is a Python library developed by the Document Analysis Group (DAG) at the Centre de Visió per Computador (CVC), within the framework of the SUKIDI project, to represent the contents of documents according to a Document Representation Model. It offers a graph-based API with two interchangeable backends – a persistent Neo4j store and an in-memory NetworkX store for testing and tutorials – together with semantic entity definitions, WeakNode hierarchies with cascade delete, foreign key validation, vector search, and ready-to-run example datasets for getting started quickly.

Features

• Two backends: Full Neo4j integration (Neo4jGraph) or in-memory NetworkX (NetworkXGraph) for testing and tutorials

• WeakNode hierarchy: Child entities with composite primary keys and automatic cascade delete through parent-child edges

• ON DELETE strategies: CASCADE, RESTRICT, SET NULL – choose the deletion semantics that fit your use case

• Semantic entities: Domain-specific node types such as IndividuPadro, LlocPadro, and Fotografia

• FK validation: Foreign key constraints on relations prevent dangling references

• Query and filtering: Secondary index on scalar properties, multi-filter search with intersection/union, debug snapshots

• Vector search (NetworkX only): HNSW-based ANN indexing on node properties with cosine, l2, and ip distance spaces

• RDF/OWL ontology conversion: Generate Python entity classes from RDF/OWL ontologies (RiC-O, etc.)

• Backend-to-backend migration: cvcdocdb.migration.migrate() copies an entire graph – nodes, edges, and vector indexes – between any two GraphStore backends

• PyTorch / PyTorch Geometric dataloader: cvcdocdb.torch_dataloader streams a graph into PyG-ready tensors for node embedding models (MetaPath2Vec) and link prediction

Installation

Install from PyPI:

pip install cvcdocdb

Optional features are installed as extras, e.g. pip install "cvcdocdb[rdf,vector]":

• rdf – RDF/OWL ontology import (cvcdocdb.rdf_schema)

• schema – entity-class generation from a YAML schema (cvcdocdb.schema_gen)

• vector – vector indexes on NetworkXGraph

• torch – PyTorch / PyG data loaders (cvcdocdb.torch_dataloader)

• graphrag – Text2Cypher on a Neo4jGraph (Python >= 3.10)

Or install from source in development mode (requirements.txt adds the documentation/notebook tools and some optional dependencies used for development):

git clone https://github.com/CVC-DAG/cvcdocdb.git
cd cvcdocdb
pip install -e . -r requirements.txt

Register the recommended Jupyter kernel for tutorials:

python -m ipykernel install --user --name cvcdocdb --display-name "Python (cvcdocdb)"

Quick Start

from cvcdocdb import NetworkXGraph, Node, WeakNode

# In-memory backend -- no database required
graph = NetworkXGraph()

# Create a document hierarchy
doc = Node(pk={"doc": "DOC-001"}, main_label="Document")
graph.insertNode(doc)

section = WeakNode(parent=doc, pk={"section": 1}, main_label="Section")
graph.insertNode(section, insert_parent=True)

page = WeakNode(parent=section, pk={"page": 1}, main_label="Page")
graph.insertNode(page, insert_parent=True)

# Query the graph
print("Nodes:", graph.get_node_ids())
print("Edges:", graph.get_edges())
graph.close()

Tutorial Notebooks

Runnable Jupyter notebooks in docs/tutorials/notebooks/. Each notebook installs the package automatically from the latest release when run.

You can also view them rendered in the hosted documentation.

RDF/OWL Ontology Conversion

Generate Python entity classes from RDF/OWL ontologies in one step:

from cvcdocdb.rdf_schema import download_ontology_and_convert

# Downloads, converts to YAML, and generates Python classes
output_path = download_ontology_and_convert(
    "https://raw.githubusercontent.com/ICA-EGAD/RiC-O/master/ontology/current-version/RiC-O_1-1.rdf",
    "rico",
    output_dir="cvcdocdb/"
)
# Generates cvcdocdb/rico_entities.py (677 classes from RiC-O)

Step by step:

from cvcdocdb.rdf_schema import download_ontology, rdf_to_yaml
from cvcdocdb.schema_gen import generate_classes

# 1. Download ontology
ont_path = download_ontology(url, output_dir="ontologies/")

# 2. Convert RDF to YAML DRM
yaml_str = rdf_to_yaml(ont_path, "my_db")

# 3. Generate Python classes
py_source = generate_classes(yaml_str)

# 4. Write file
with open("cvcdocdb/entities_my_db.py", "w") as f:
    f.write(py_source)

The pipeline maps OWL constructs to DRM:

• owl:Class – Node label

• rdfs:subClassOf – WeakNode hierarchy (parent)

• owl:DatatypeProperty – Node properties

• owl:ObjectProperty – Relationships

• owl:hasKey – Primary key fields

• rdfs:comment – Class docstring

Example Dataset Loaders (cvcdocdb.exemples)

The package includes ready-to-run loaders for common graph domains:

• cvcdocdb.exemples.networkx_karate – Karate Club graph (NetworkX classic)

• cvcdocdb.exemples.networkx_bibliografia – Bibliographic references from OpenAlex

• cvcdocdb.exemples.neo4j_movies – Movie-domain graph

• cvcdocdb.exemples.neo4j_got – Game of Thrones character-house graph

python -m cvcdocdb.exemples --dataset karate --backend networkx
python -m cvcdocdb.exemples --dataset all --backend both --quiet

from cvcdocdb import NetworkXGraph
from cvcdocdb.exemples import load_karate_club, load_bibliografia_openalex

graph = NetworkXGraph()
print(load_karate_club(graph))
print(load_bibliografia_openalex(graph, query="graph database", per_page=15))
graph.close()

Configuration

CVCDocDB uses environment variables for Neo4j connections. Multiple targets are supported via the NEO4J_TARGET selector:

# Default target
export NEO4J_DEV_URL=bolt://dev-host:7687
export NEO4J_DEV_USER=neo4j
export NEO4J_DEV_PASSWORD=your_dev_password
export NEO4J_DEV_DATABASE=neo4j

# Custom target
export NEO4J_TARGET=LOCAL
export NEO4J_LOCAL_URL=bolt://localhost:7687
export NEO4J_LOCAL_USER=neo4j
export NEO4J_LOCAL_PASSWORD=your_password
export NEO4J_LOCAL_DATABASE=neo4j

Running Tests

pip install -r requirements-test.txt
python -m pytest test/ -v

Three test levels:

• Unit (-m unit) – fast, no graph store

• Integration (-m integration) – NetworkXGraph (in-memory)

• Neo4j (-m slow) – requires a real Neo4j connection. If none is reachable and Docker is available, a disposable neo4j:5-community container is started automatically; otherwise these tests auto-skip. See test/README.md for details and the manual docker-compose.neo4j.yml option.

Skip Neo4j tests: pytest test/ -v -m "not slow"

Documentation

• Hosted docs: https://cvc-dag.github.io/cvcdocdb/

• Source docs: docs/ – Sphinx documentation source

Generate HTML docs with Sphinx:

cd docs
sphinx-build -b html . _build/html

Authors and Contributors

• Oriol Ramos Terrades

• Jialuo Chen

• Adrià Molina

Acknowledgements

This work has been partially supported by the Spanish projects PID2021-126808OB-I00 and PID2024-157778OB-I00, Ministerio de Ciencia e Innovación, the Departament de Cultura of the Generalitat de Catalunya, and the CERCA Program / Generalitat de Catalunya. Adrià Molina is funded with the PRE2022-101575 grant provided by MCIN / AEI / 10.13039 / 501100011033 and by the European Social Fund (FSE+).