This Ruby script fills in the blanks in a csv file which has "rowspan".

rowspan_csv.rb

require 'csv'

FILE_IN = "in.csv"
FILE_OUT = "out.csv"

CSV.open(FILE_OUT, "wb") do |out|

  CSV.foreach(FILE_IN) do |row|
    @complete_row ||= row
    row.each_with_index {|v,i| @complete_row[i] = v if v }
    out << @complete_row
  end

end

Example:

A file that looks like:

Owner,Dog,Food
Tim,Struppi,Bones
,,Meat
Michey,Pluto,Sausage

will be converted to:

Owner,Dog,Food
Tim,Struppi,Bones
Tim,Struppi,Meat
Michey,Pluto,Sausage