September 2023
Intermediate to advanced
367 pages
7h 23m
English
Content preview from Go Cookbook
Become an O’Reilly member and get unlimited access to this title plus top books and audiobooks from O’Reilly and nearly 200 top publishers, thousands of courses curated by job role, 150+ live events each month,
O’Reilly covers everything we've got, with content to help us build a world-class technology community, upgrade the capabilities and competencies of our teams, and improve overall team performance as well as their engagement.I wanted to learn C and C++, but it didn't click for me until I picked up an O'Reilly book. When I went on the O’Reilly platform, I was astonished to find all the books there, plus live events and sandboxes so you could play around with the technology.I’ve been on the O’Reilly platform for more than eight years. I use a couple of learning platforms, but I'm on O'Reilly more than anybody else. When you're there, you start learning. I'm never disappointed.I'm always learning. So when I got on to O'Reilly, I was like a kid in a candy store. There are playlists. There are answers. There's on-demand training. It's worth its weight in gold, in terms of what it allows me to do.
Chapter 8. CSV Recipes
8.0 Introduction
The CSV (comma-separated values) format is a file format in which tabular data (numbers and text) can be easily written and read in a text editor. CSV is widely supported, and most spreadsheet programs, such as Microsoft Excel and Apple Numbers, support CSV. Consequently, many programming languages, including Go, come with libraries that produce and consume the data in CSV files.
It might surprise you that CSV has been around for more than 50 years. The IBM Fortran compiler supported it in OS/360 back in 1972. If you’re not quite sure what that is, OS/360 is the batch processing operating system developed by IBM for its System/360 mainframe computer. So yes, one of the first uses for CSV was for Fortran in an IBM mainframe computer.
CSV is not very standardized, and not all CSV formats are separated by commas, either. Sometimes it can be a tab or a semicolon or other delimiters. However, there is an RFC specification for CSV—RFC 4180, though not everyone follows that standard.
The Go standard library has an encoding/csv package that supports RFC 4180 and helps you read and write CSV.
8.1 Reading the Whole CSV File
Problem
You want to read a CSV file into memory for use.
Solution
Use the encoding/csv package and csv.ReadAll to read all data in the CSV file into a 2D array of strings.
Discussion
Say you have a file like this:
id,first_name,last_name,email 1,Sausheong,Chang,sausheong@email.com 2,John,Doe,john@email.com
The first row ...
Become an O’Reilly member and get unlimited access to this title plus top books and audiobooks from O’Reilly and nearly 200 top publishers, thousands of courses curated by job role, 150+ live events each month,
and much more.
Read now
Unlock full access
More than 5,000 organizations count on O’Reilly
O’Reilly covers everything we've got, with content to help us build a world-class technology community, upgrade the capabilities and competencies of our teams, and improve overall team performance as well as their engagement.Julian F.
I wanted to learn C and C++, but it didn't click for me until I picked up an O'Reilly book. When I went on the O’Reilly platform, I was astonished to find all the books there, plus live events and sandboxes so you could play around with the technology.Addison B.
I’ve been on the O’Reilly platform for more than eight years. I use a couple of learning platforms, but I'm on O'Reilly more than anybody else. When you're there, you start learning. I'm never disappointed.Amir M.
I'm always learning. So when I got on to O'Reilly, I was like a kid in a candy store. There are playlists. There are answers. There's on-demand training. It's worth its weight in gold, in terms of what it allows me to do.