Working with Excel in Rust: Libraries for Reading and Writing

Working with Excel in Rust: Overview of Libraries and Code Examples

Rust is a systems programming language increasingly used for creating high-performance utilities, including for processing tabular data. Unlike Python, where pandas or openpyxl are the standard, the Rust ecosystem for working with Excel is smaller but offers several mature and fast solutions. In this article, we will cover three main libraries: rust_xlsxwriter (writing), calamine (reading), and xlsx (universal). You will learn how to read, create, and modify XLSX files using Rust.

Why Use Rust for Excel?

The main advantages of Rust when working with spreadsheets:

• Speed — compiled code processes millions of rows faster than interpreted alternatives.
• Safety — a strict type system and ownership model prevent memory leaks and access errors.
• Cross-platform — binaries run on Windows, Linux, macOS without dependencies.
• Small size — the final executable file can be less than 5 MB.

1. Writing Excel: rust_xlsxwriter

rust_xlsxwriter is a fork of the popular xlsxwriter library, adapted for Rust. It allows you to create XLSX files from scratch, supports formatting, cell merging, charts, and custom styles.

Installation:

// Cargo.toml[dependencies]rust_xlsxwriter = "0.64"

Example: Creating a Simple Report

use rust_xlsxwriter::*;

fn main() -> Result<(), XlsxError> {    let mut workbook = Workbook::new();    let sheet = workbook.add_worksheet();

    // Header    let header_format = Format::new()        .set_bold()        .set_font_color(Color::White)        .set_background_color(Color::Blue);

    sheet.write_string_with_format(0, 0, "Name", &header_format)?;    sheet.write_string_with_format(0, 1, "Sales", &header_format)?;    sheet.write_string_with_format(0, 2, "Date", &header_format)?;

    // Data    let data = vec![        ("Product A", 1500, "2024-01-15"),        ("Product B", 2300, "2024-01-16"),        ("Product C", 800,  "2024-01-17"),    ];

    for (row, (name, sales, date)) in data.iter().enumerate() {        sheet.write_string(row as u32 + 1, 0, name)?;        sheet.write_number(row as u32 + 1, 1, *sales as f64)?;        sheet.write_string(row as u32 + 1, 2, date)?;    }

    // Auto column width    sheet.set_column_width(0, 15)?;    sheet.set_column_width(1, 12)?;    sheet.set_column_width(2, 14)?;

    workbook.save("report.xlsx")?;    println!("File report.xlsx created");    Ok(())}

The library supports all basic types: numbers, strings, dates, formulas, hyperlinks. Fonts, fills, borders, and alignment are available for formatting.

2. Reading Excel: calamine

calamine is a fast parser for XLSX/XLS/XLSB/ODS files. It has no external dependencies and works for reading only. It is ideal for extracting data from large spreadsheets.

Installation:

[dependencies]calamine = "0.24"

Example: Reading All Data from a Sheet

use calamine::{open_workbook, Reader, Xlsx};

fn main() -> Result<(), Box> {    let path = "report.xlsx";    let mut workbook: Xlsx<_> = open_workbook(path)?;

    // Get the first sheet    if let Some(Ok(range)) = workbook.worksheet_range("Sheet1") {        for row in range.rows() {            for cell in row {                // Output the cell value as a string                print!("{} | ", cell.to_string());            }            println!();