csvutil - Your CSV pocket-knife (golang)

This is csvutil version 1.1_2

The csvutil package can be used to read CSV data from any io.Reader and, write CSV data to any io.Writer. It can automatically generate CSV rows from slices containing native Go types, other slices/arrays of native go types, or flat structs. It can also convert CSV rows and assign values to memory referenced by a slice of pointers.

package main
import "os"
import "github.com/bmatsuo/csvutil"

type Person struct {
    Name   string
    Height float64
    Weight float64
}

func main() {
    writer := csvutil.NewWriter(os.Stdout, nil)
    errdo := csvutil.DoFile(os.Args[1], func(r csvutil.Row) bool {
        if r.HasError() {
            panic(r.Error)
        }
        var person Person
        if _, errc := r.Format(&person); errc != nil {
            panic("Row is not a Person")
        }
        bmi := person.Weight / (person.Height * person.Height)
        writer.WriteRow(csvutil.FormatRow(person, bmi).Fields...)
        return true
    })
    if errdo != nil {
        panic(errdo)
    }
    writer.Flush()
}

Given a CSV file 'in.csv' with contents

alice,1.4,50
bob,2,80
chris,1.6,67

When the above program is called and given the path 'in.csv', the following is printed to standard output.

alice,1.4,50,25.510204081632658
bob,2,80,20
chris,1.6,67,26.171874999999996

The csvutil package is written to make interacting with CSV data as easy as possible. Efficiency of its underlying functions and methods are slightly less important factors in its design. However, that being said, it is important. And, csvutil should be capable of handling both extremely large and fairly small streams of CSV data through input and output quite well in terms of speed and memory footprint. It should do this while not making your code bend over backwards (more than necessary). As libraries should never make you do.

• Slurping/spewing CSV data. That is, reading/writing whole files or data streams at once.

• Iteration through individual rows of a CSV data stream for a smaller memory footprint.

• Writing of individual writing fields/rows (along with batch writing).

• Automated CSV row serialization and deserialization (formatting) for flat data structures and types.

• Enhance and clean the formatting API and allow better formatting of data.

The easiest installation of csvutil is done through goinstall.

goinstall github.com/bmatsuo/csvutil

The best way to read the current csvutil documentation is using godoc.

godoc github.com/bmatsuo/csvutil

Or better yet, you can run a godoc http server.

godoc -http=":6060"

Then go to the url http://localhost:6060/pkg/github.com/bmatsuo/csvutil/

Copyright (c) 2011, Bryan Matsuo. All rights reserved.

Use of this source code is governed by a BSD-style license that can be found in the LICENSE file.