CSV Tool Pro

Perform comprehensive CSV file operations including viewing, filtering, sorting, merging, splitting, deduplication, conversion (JSON/YAML/TSV/Markdown/HTML),...

Author: Lin Hui | GitHub | MIT License | v1.0.0

One command to rule all your CSV files. View, filter, sort, merge, split, dedupe, convert, and analyze — all without leaving your terminal or opening Excel.

✨ Features

Core Operations

• View — Pretty-print CSV with alignment and truncation
• Filter — Row filtering by column value, regex, or numeric range
• Sort — Single or multi-column sort (asc/desc)
• Dedupe — Remove duplicate rows by key columns

Multi-File Operations

• Merge — Combine multiple CSVs (union by headers)
• Join — Inner/left/right/full join on key columns
• Split — Split large CSV into smaller files by row count or column value

Format Conversion

• to JSON — Array of objects or nested format
• to YAML — Clean YAML output
• to TSV — Tab-separated output
• to Markdown — GitHub-flavored markdown table
• to HTML — Styled HTML table

Analytics

• Stats — Count, mean, median, min, max, std for numeric columns
• Frequency — Value frequency distribution
• Pivot — Pivot table aggregation

🚀 Usage

View a CSV file

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Read the CSV file at /path/to/data.csv and show the first 20 rows in a nice table.

Filter and sort

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Read sales.csv, filter rows where amount > 1000, sort by date descending.

Merge multiple CSVs

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Merge january.csv and february.csv into a single file Q1.csv.

Convert to JSON

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Convert users.csv to JSON format and save as users.json.

Stats

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Show statistics for all numeric columns in metrics.csv.

Dedupe

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Remove duplicate rows from contacts.csv based on the email column.

Pivot table

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Create a pivot table from sales.csv with region as rows, product as columns, sum of amount as values.

⚙️ Technical Details

• Runtime: Python 3.6+
• Dependencies: Zero (stdlib only: csv, json, statistics, re, argparse, os)
• Encoding: Auto-detect UTF-8/GBK/UTF-8-BOM
• Large files: Streaming processing for files >100MB
• Delimiters: Auto-detect comma, tab, semicolon, pipe

📝 Notes

• Auto-detects delimiter (comma, tab, semicolon, pipe)
• Handles quoted fields with embedded delimiters and newlines
• Preserves original encoding on write
• Supports gzip-compressed CSV files