Automatically Generating yEd Diagrams from Metadata with Python

How to turn metadata into lineage diagrams, ERDs, and business-friendly mappings — and let yEd handle the layout.

Summary

Creating lineage, impact analysis, and ERD diagrams by hand is slow and fragile.

In this article, I show how to generate GraphML with Python and open it directly in yEd (free). With one click of yEd’s autolayout, your metadata becomes a clean, professional diagram.

We’ll cover:

• Why yEd is a great (free) visualization engine
• A tiny Python “package” (helper module) for building GraphML
• Examples: Lineage, ERD with crow’s-foot, and combined ERD + Lineage with swimlanes
• Optionality (0..N) vs mandatory (1..N) using dashed vs solid edges
• Demo code you can copy-paste

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Why yEd?

yEd Graph Editor is a free, desktop graph tool from yWorks. It loads GraphML (XML for graphs), supports thousands of nodes, and has world-class layout algorithms (Hierarchical, Orthogonal, Organic, Circular, etc.). Because GraphML is just text, we can generate it directly from DuckDB…