File Validator Tool

This project provides a reusable framework to compare fixed-width file outputs between a legacy sytem and a modernised application

Features

• ⁠Fixed-width file parsing driven by a mapping document
• ⁠Field-level comparison using a base file as reference
• ⁠Excel validation report with:
  1. Summary sheet
  2. Field-specific worksheets highlighting mismatches
• ⁠Streamlit-based UI for uploading input files and mappings

Tech Stack

•⁠ ⁠Python •⁠ ⁠Streamlit •⁠ ⁠OpenPyXL

Run

1. Install dependencies:
   • pip install -r requirements.txt
2. Update current shell to use venv's Python and packages
   • source .venv/bin/activate
3. Start the UI:
   • python -m streamlit run app.py

How to use the application

• Upload the Base and Validation files.
• Provide the mapping CSV either via upload or by updating the path in the sidebar.
• Click Generate Report, then download the Excel report.

Use Cases

• ⁠Data validation during application migration
• ⁠Regression testing for reporting systems
• Automated reconciliation of batch outputs

Disclaimer

This project uses synthetic data and is a generalized implementation inspired by real-world migration scenarios. It does not contain proprietary or sensitive information.