CSV Export Comparison: Added, Removed & Changed Records

Find changes between two exports

Independent portfolio project · Synthetic data · AI-assisted development

A small reusable Python utility compares two CSV exports by a stable identifier. It reports additions, removals, changed fields and unchanged IDs. Missing or duplicate IDs stop processing for review instead of allowing ambiguous matches. Neither input is modified.

The demonstration reports P4 added, P2 removed, P1 stock changing from 12 to 10, and P3 unchanged. These are fictional inventory records.

Reproducible deliverables Dependency-free Python source, fictional before/after CSVs, a JSON difference report, five automated tests and an operating guide. All five tests passed again on November 9, 2026. Checks cover exact changes, duplicate IDs, missing IDs, empty inputs and source preservation.

Scope and limitations This compares text exactly. Client-specific normalization must be agreed separately; renamed identifiers appear as a removal and addition. It has not been tested against live CRM systems or large datasets. Suggested use is to reconcile exports or identify changes before a human-approved import. It does not write to a live system or make inventory decisions.