#!/usr/bin/env ruby
# -*- coding: utf-8 -*-

require'csv'

csv  = CSV.generate("test.csv",headers: true) do |csv|
  csv.add_row(["written","by","csv.rb"])
end
print csv                       # このファイル内での話。

=begin
CSV.open("test.csv","a") do|test2|
  test2 << ["written","by","csv.rb"]
end
print File.read("test.csv")     # csvへの書き込みはこっち。
=end