How to Read and Write CSV Files in Rust

Use the csv crate to read and write CSV files efficiently in Rust. Add csv = "1.3" to your Cargo.toml, then use Reader for parsing and Writer for output.

use csv::{Reader, Writer};
use std::fs::File;

fn main() -> Result<(), Box<dyn std::error::Error>> {
    // Read
    let file = File::open("data.csv")?;
    let mut rdr = Reader::from_reader(file);
    for result in rdr.records() {
        let record = result?;
        println!("{:?}", record);
    }

    // Write
    let file = File::create("output.csv")?;
    let mut wtr = Writer::from_writer(file);
    wtr.write_record(&["id", "name"])?;
    wtr.write_record(&["1", "Alice"])?;
    wtr.flush()?;
    Ok(())
}

The csv crate is a tool that handles the messy details of reading and writing comma-separated data. It automatically splits lines into columns and handles special characters so you don't have to write complex parsing logic. Think of it as a dedicated translator that turns raw text files into structured data your program can use immediately.