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Version: Next

Generator CLI Tool

Generator CLI Tool​

The Python client includes a CLI tool that allows you to generate Python classes from OpenLineage specification files. This is particularly useful if you want to:

  • Create custom facets based on your own JSON schema definitions
  • Generate client code that matches a specific version of the OpenLineage specification
  • Extend the OpenLineage model with domain-specific classes

Dependencies​

The CLI tool requires datamodel-code-generator, a library that converts JSON Schema to Python data models. If you plan to use the generator, install it with:

pip install "openlineage-python[generator]"

Usage​

ol-generate-code [FACETS_SPEC_LOCATION] [--output-location OUTPUT_LOCATION]

Arguments​

  • FACETS_SPEC_LOCATION: Path to a JSON file or directory containing JSON files with OpenLineage facet specifications
  • --output-location: (Optional) Directory where the generated Python classes will be saved. If not specified, output will be printed to stdout with proposed file names.

Examples​

Generate Python classes from a single facet specification file:

ol-generate-code my_custom_facet.json --output-location ./generated_code

Generate Python classes from a directory containing multiple facet specification files:

ol-generate-code ./facets_dir --output-location ./generated_code

How It Works​

The CLI tool:

  1. Retrieves the base OpenLineage specification from https://openlineage.io/spec/2-0-2/OpenLineage.json
  2. Loads and parses your custom facet specifications
  3. Uses the datamodel-code-generator library to generate Python classes that match the structure of the specifications
  4. Formats the generated code using Ruff. The generator automatically converts camelCase names to snake_case for Python conventions
  5. Outputs the files to the specified location