I investigate and fix one reproducible issue in a small Python script that imports, transforms or exports CSV or JSON data. Please contact me before purchasing so we can agree on the expected behavior and scope.

You receive a source patch, a regression test covering the original failure, results from relevant checks, clear run instructions and a short explanation. One revision within the agreed issue is included. Delivery: 3 days after scope and required materials are confirmed.

Best fit: duplicate handling, parsing errors, validation and incorrect transformations. New features, production deployment, full application audits and paid external services require separate scope.

Please provide the relevant source files, Python version, dependencies, exact command, redacted traceback and a small synthetic input with expected output. Remove credentials and personal records.

AI tools may assist development. Code and test results are reviewed before delivery. Any use of client material in an external AI service must be agreed first.

Independent demonstration results are available on request (AI-assisted, not a client commission). Please message me for a relevant example.

The CSV demo reports duplicate records and row-width problems without modifying input files. Five local tests covered leading-zero identifiers, Unicode, quoted multiline fields and malformed input.