prettytable

PrettyTable

A CLI based Node.js module for generating and displaying pretty ASCII tables from multiple data sources.

• 📊 Generate tables from arrays, CSV, or JSON data
• 🔍 Sort, filter, and manipulate table data
• 🖨️ Output as plain text or HTML
• 🛠️ Modern JavaScript with comprehensive error handling

Installation

npm install prettytable

Basic Usage

Create a table with headers and rows in one shot:

// Import and instantiate
const PrettyTable = require("prettytable");
const pt = new PrettyTable();

// Define headers and data
const headers = ["Name", "Age", "City"];
const rows = [
  ["John", 22, "New York"],
  ["Elizabeth", 43, "Chicago"],
  ["Bill", 31, "Atlanta"],
  ["Mary", 18, "Los Angeles"],
];

// Create and display table
pt.create(headers, rows);
pt.print();

Output:

+-----------+-----+-------------+
| Name      | Age | City        |
+-----------+-----+-------------+
| John      | 22  | New York    |
| Elizabeth | 43  | Chicago     |
| Bill      | 31  | Atlanta     |
| Mary      | 18  | Los Angeles |
+-----------+-----+-------------+

Build a table row-by-row:

const PrettyTable = require("prettytable");
const pt = new PrettyTable();

// Set column names
pt.fieldNames(["City", "Area", "Population", "Rainfall"]);

// Add rows one by one
pt.addRow(["Adelaide", 1295, 1158259, 600.5]);
pt.addRow(["Brisbane", 5905, 1857594, 1146.4]);
pt.addRow(["Darwin", 112, 120900, 1714.7]);
pt.addRow(["Hobart", 1357, 205556, 619.5]);
pt.addRow(["Sydney", 2058, 4336374, 1214.8]);
pt.addRow(["Melbourne", 1566, 3806092, 646.9]);
pt.addRow(["Perth", 5386, 1554769, 869.4]);

// Display the table
pt.print();

Data Import Features

Import from CSV

const PrettyTable = require("prettytable");
const pt = new PrettyTable();

// Load from CSV file (first row is used as headers)
pt.csv("./data.csv");
pt.print();

Import from JSON

const PrettyTable = require("prettytable");
const pt = new PrettyTable();

// Load from JSON file (object keys become headers)
pt.json("./data.json");
pt.print();

Output Options

Return as String

Get the table as a formatted string:

const PrettyTable = require("prettytable");
const pt = new PrettyTable();

pt.fieldNames(["Name", "Age", "City"]);
pt.addRow(["John", 25, "New York"]);
pt.addRow(["Mary", 30, "Chicago"]);

const tableString = pt.toString();
console.log(tableString);

Generate HTML

Create an HTML table representation:

const PrettyTable = require("prettytable");
const pt = new PrettyTable();

pt.fieldNames(["Name", "Age", "City"]);
pt.addRow(["John", 25, "New York"]);
pt.addRow(["Mary", 30, "Chicago"]);

// Basic HTML table
const basicHtml = pt.html();

// HTML table with custom attributes
const styledHtml = pt.html({
  id: "data-table",
  class: "table table-striped",
  border: "1",
});

Table Manipulation

Sort by Column

const PrettyTable = require("prettytable");
const pt = new PrettyTable();

pt.fieldNames(["Name", "Age", "City"]);
pt.addRow(["John", 22, "New York"]);
pt.addRow(["Elizabeth", 43, "Chicago"]);
pt.addRow(["Bill", 31, "Atlanta"]);
pt.addRow(["Mary", 18, "Los Angeles"]);

// Sort by age (ascending)
pt.sortTable("Age");
pt.print();

// Sort by name (descending)
pt.sortTable("Name", true);
pt.print();

Delete and Modify Data

const PrettyTable = require("prettytable");
const pt = new PrettyTable();

pt.fieldNames(["Name", "Age", "City"]);
pt.addRow(["John", 22, "New York"]);
pt.addRow(["Elizabeth", 43, "Chicago"]);
pt.addRow(["Bill", 31, "Atlanta"]);
pt.addRow(["Mary", 18, "Los Angeles"]);

// Delete the second row (Elizabeth)
pt.deleteRow(2);
pt.print();

// Clear all rows but keep the structure
pt.clearTable();
pt.print();

// Delete the entire table
pt.deleteTable();

Error Handling

PrettyTable includes comprehensive error handling for all methods:

const PrettyTable = require("prettytable");
const pt = new PrettyTable();

try {
  pt.fieldNames(["Name", "Age", "City"]);
  pt.addRow(["John", 22]); // Error: Row length doesn't match columns
} catch (error) {
  console.error(`Error: ${error.message}`);
}

API Reference

The PrettyTable module provides the following methods:

Method	Description
fieldNames(array)	Define column headers
addRow(array)	Add a single row
create(headers, rows)	Create table with headers and rows
toString()	Return table as a formatted string
print()	Print table to console
html([attributes])	Generate HTML representation
csv(filename)	Import data from CSV file
json(filename)	Import data from JSON file
sortTable(column, [reverse])	Sort by column
deleteRow(rownum)	Delete a specific row
clearTable()	Remove all rows
deleteTable()	Delete entire table

Contributing

This project welcomes contributions! The codebase uses ESLint for code quality and Mocha/Chai for testing.

# Install dependencies
npm install

# Run linter
npm run lint

# Fix automatically fixable issues
npm run lint:fix

# Run tests
npm test

License

This project is licensed under the MIT License - see the LICENSE file for details.