rspreadsheet gem usage example (https://github.com/gorn/rspreadsheet)

rspreadsheet.rb

require 'rspreadsheet'
book = Rspreadsheet.open('./test.ods')
sheet = book.worksheets(1)


# get value of a cell B5 (there are more ways to do this)
sheet.B5                       # => 'cell value'
sheet[5,2]                     # => 'cell value'
sheet.row(5).cell(2).value   # => 'cell value'

# set value of a cell B5
sheet.F5 = 'text'
sheet[5,2] = 7
sheet.cell(5,2).value = 1.78

# working with cell format
sheet.cell(5,2).format.bold = true
sheet.cell(5,2).format.background_color = '#FF0000'

# calculating sum of cells in row
sheet.row(5).cellvalues.sum
sheet.row(5).cells.sum{ |cell| cell.value.to_f }

# iterating over list of people and displaying the data

total = 0
sheet.rows.each do |row|
  puts "Sponsor #{row[1]} with email #{row[2]} has donated #{row[3]} USD."
  total += row[3].to_f
end
puts "Totally fundraised #{total} USD"

# saving file
book.save
book.save('different_filename.ods')

In that particular case it would be better to use #reduce instead of #each in line #27.

@zekefast I agree that this is not a best example, it was intended like example of simple iteration