📊 CSV Tool Pro

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

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

Filter and sort

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

Merge multiple CSVs

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

Convert to JSON

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

Stats

Show statistics for all numeric columns in metrics.csv.

Dedupe

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

Pivot table

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