filldown

1 project · 2 posts

Projects

xlfilldown: The Complete Guide to Excel Fill Down

The xlfilldown tool is a CLI and Python library designed for processing Excel data into SQLite or new Excel workbooks. It efficiently handles hierarchical and independent fill modes to maintain data integrity. Key features include row hashing, constant-memory processing, and raw ingestion options. Users can choose between CLI commands or a Python API for seamless integration into their workflows.

Sep 23, 2025

Posts

The Secret Hierarchies of Excel: Why Managers Merge, and Engineers Cry

Excel may appear simple, but it conceals a daunting data challenge: the hierarchical spreadsheet. Common among analysts, it presents issues like merged cells and hidden hierarchies that frustrate data processing. Enter xlfilldown—a powerful solution that transforms chaotic Excel files into clean, structured datasets for seamless analysis. By bridging the gap between visual reports and data integrity, xlfilldown revolutionizes the ETL process for data professionals.

Oct 13, 2025

One Million Rows: Testing xlfilldown Performance and Constant-Memory Design

The content discusses the performance and reliability of the xlfilldown tool, which efficiently processes large Excel datasets without excessive memory usage. A stress test processing 1,000,000 rows demonstrated rapid speeds—13,800 rows/sec for Excel and 44,700 rows/sec for SQLite—while maintaining deterministic and auditable output. This enhances data integrity and workflow trust.

Oct 6, 2025