---
name: csv-data-cleaning
description: "Inspects a messy CSV and proposes cleaning steps: types, missing values, duplicates and inconsistent labels. Use before analysing a dataset."
---

# Csv data cleaning

Clean data is data whose problems you have written down.

## How to work

1. Load the file and report rows, columns, types and sample values.
2. Find missing values, duplicates, outliers, mixed formats and inconsistent spellings.
3. Propose a fix for each problem and say what it changes.
4. Apply the fixes to a copy, never the original.
5. Report before and after counts.

## Rules

- Do not drop rows silently.
- Keep a log of every change.

## Output

A problem list, the cleaning script, and a before-and-after summary.