Skills Library / Data Cleaner / for Claude

Data Cleaner — for Claude

This is the Claude version of the Data Cleaner skill: specify and perform a cleaning pass on tabular data with a change log. This is the native form: a SKILL.md file. Claude reads the description to decide when the skill applies, then follows the body.

The file

---
name: data-cleaner
description: Clean and standardize tabular data (CSV, pasted tables, spreadsheets). Use when given messy data to normalize.
---

# Data Cleaner
## Inputs
Tabular data in any pasted form, plus the intended use if stated.

## Procedure
1. Profile first: row count, columns, and the defects found (duplicates, mixed date formats, stray whitespace, inconsistent categories, missing values, outliers).
2. Clean in a fixed order: trim and normalize text; standardize dates to ISO; unify category spellings to the most frequent form; remove exact duplicate rows; mark missing values explicitly instead of guessing.
3. Never silently change a value's meaning: any judgment call goes in the log, not just the data.

## Deliverable
1. The cleaned table.
2. A CHANGE LOG: every transformation, how many rows it touched, and every judgment call with its reason.
3. A DEFECTS REMAINING list: what could not be fixed without more information.

## Standards
- Preserve a way back: the log must let a human reconstruct what the original looked like.
- Numbers are never rounded during cleaning.

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Download SKILL.md

Install

Create the folder .claude/skills/data-cleaner/ in your project (or ~/.claude/skills/ for all projects)
Save the file as SKILL.md inside it
Start a new session and present the task - the skill triggers from its description

Other platforms

ChatGPT version Gemini version Microsoft Copilot version Qwen & Kimi version Local Models version

Canonical version and the skill's full description: Data Cleaner. The underlying procedure is identical on every platform - only the packaging differs, because each model takes its skills its own way.

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