Working with Excel in Rust: Libraries for Reading and Writing Spreadsheets

Working with Excel in Rust: Library Overview and Code Examples

The Rust language, known for its performance and safety, provides excellent capabilities for working with Excel spreadsheets. In this article, we will look at three of the most popular libraries: rust_xlsxwriter, calamine, and xlsx. You will learn how to read, create, and modify .xlsx files, as well as how to apply advanced formatting features.

Why Rust for Working with Excel?

Rust is ideal for data processing tasks due to:

• Zero-cost abstractions — high speed when working with large files;
• Safe memory management — eliminating leaks and segmentation faults;
• Cross-platform compatibility — code runs on Windows, macOS, and Linux;
• Excellent integration with other systems via FFI.

The rust_xlsxwriter Library: Creating Excel Files

rust_xlsxwriter is a modern library for creating Excel files with rich formatting capabilities. It supports styles, cell merging, formulas, and conditional formatting.

Installation

Add to Cargo.toml:

[dependencies]rust_xlsxwriter = "0.77"

Example: Creating a Formatted Report

Let's create a file with headers, data, and a formula:

use rust_xlsxwriter::*;

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

    // Create styles    let header_format = Format::new()        .set_bold()        .set_font_color(Color::White)        .set_background_color(Color::Blue)        .set_border(FormatBorder::Thin);

    let money_format = Format::new()        .set_num_format("$#,##0.00")        .set_border(FormatBorder::Thin);

    // Headers    worksheet.write_with_format(0, 0, "Product", &header_format)?;    worksheet.write_with_format(0, 1, "Quantity", &header_format)?;    worksheet.write_with_format(0, 2, "Price", &header_format)?;    worksheet.write_with_format(0, 3, "Total", &header_format)?;

    // Data    let items = vec![        ("Laptop", 5, 1200.00),        ("Mouse", 10, 25.50),        ("Keyboard", 7, 45.00),    ];

    for (i, (name, qty, price)) in items.iter().enumerate() {        let row = i as u32 + 1;        worksheet.write(row, 0, name)?;        worksheet.write(row, 1, *qty)?;        worksheet.write_with_format(row, 2, *price, &money_format)?;        // Formula: quantity * price        worksheet.write_formula(row, 3, &format!("B{}*C{}", row+1, row+1))?;    }

    // Auto-width columns    worksheet.set_column_width(0, 15)?;    worksheet.set_column_width(1, 12)?;    worksheet.set_column_width(2, 10)?;    worksheet.set_column_width(3, 12)?;

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

The calamine Library: Reading Excel Files

calamine is a fast parser for reading Excel files (.xlsx, .xls, .xlsb). It does not require Excel to be installed and works entirely in memory.

Installation

[dependencies]calamine = "0.24"

Example: Reading Data from a File

Let's read the previously created file and output the data to the console:

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

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

    if let Some(Ok(range)) = workbook.worksheet_range("Sheet1") {        println!("Contents of file {}:", path);        println!("{:-<40}", "");

        for row in range.rows() {            for cell in row {                match cell {                    calamine::Data::Stri