This is the quick problem/solution index. Start with the accounting task you recognize, then jump to the relevant PANDAUDIT guide.

Lookups, joins, and reconciliations

### How do I replace VLOOKUP in pandas? Use `merge` to join two tables by a shared key, then check for missing matches. - [When VLOOKUP Fails You: Merge Functions](/2026-01-26-when-vlookup-fails-you-merge-functions/) - [Merge Excel and SQL Databases Safely](/2026-01-15-merge-excel-sql-databases-safely/) ### How do I find transactions in one report but not another? Use an outer merge with `indicator=True`, then filter anything not matched on both sides. - [The Copy-Paste Nightmare: Automated Reconciliations](/2026-01-25-the-copy-paste-nightmare-automated-reconciliations/) - [Data Analytics Quick Reference](/cheatsheet/#reconciliation-techniques) ### How do I match records when dates are close but not exact? Use `merge_asof` for nearest-date matching. - [Performing More Complex Merges](/2020-05-05-Performing-more-complex-merges/) - [Streamline Data Analysis With Python's merge_asof Function](/2023-07-02-Streamline-data-analysis-with-pythons's-merge_as_of-function/)

Cleaning messy exports

How do I clean negative numbers exported like 1,234.56- or 1,234CR?

Normalize the text first, move the sign to the front, then convert to a number.

How do I extract dollar amounts from descriptions?

Use string methods and regular expressions to pull numbers out of text.

How do I clean inconsistent account/vendor names?

Standardize case, whitespace, punctuation, and known abbreviations before comparing.

Summaries and reporting

How do I replace a Pivot Table?

Use pivot_table for spreadsheet-style summaries and groupby for programmatic summaries.

How do I create monthly or fiscal-year summaries?

Convert dates once, add a period/fiscal column, then group by it.

How do I export a clean Excel workbook with multiple tabs?

Use ExcelWriter and write each output table to its own sheet.

Quality checks and audit-style testing

How do I find duplicates without losing the details?

Use duplicated(keep=False) to show every row involved in duplicate groups.

How do I spot unusual transactions?

Start with round numbers, weekends, outliers, and missing master-data matches.

Have a recipe request?

Bring a sanitized version of your spreadsheet problem to the PANDAUDIT Discord. The best new questions become future recipes.