DataDesigner/docs/recipes/plugin_development/markdown_seed_reader.md

Markdown Section Seed Reader

Turn a directory of Markdown files into a seed dataset with one row per section. This recipe stays in the same single-file format as the other recipes: it creates sample files, defines an inline FileSystemSeedReader[DirectorySeedSource], and passes that reader to DataDesigner(seed_readers=[...]).

This keeps the example focused on the actual seed reader contract:

• implementing build_manifest(...)
• returning 1:N hydrated rows from hydrate_row(...)
• declaring output_columns for the hydrated schema
• keeping IndexRange selection manifest-based

Because the example reuses DirectorySeedSource, it does not register a brand-new seed_type. To package the same reader as an installable plugin, see Build Your Own.

Run the Recipe

Run the script directly:

uv run markdown_seed_reader.py

The script prints two previews:

• the full section dataset across all Markdown files
• a manifest-only selection using IndexRange(start=1, end=1) that still returns every section from the selected file

Download Code :octicons-download-24:{ .md-button download="markdown_seed_reader.py" }

--8<-- "assets/recipes/plugin_development/markdown_seed_reader.py"