RubyのExcel操作ライブラリ'Roo'の実装例

roo-example.rb

require 'roo'

s = Roo::Excelx.new('test.xlsx')
s.default_sheet = s.sheets[0]

columns = ('A'..'Z')
rows = (1..10)

columns.each do |c|
  rows.each do |r|
    s.cell(c, r)
  end
end