Ruby 1.9.2 リファレンスマニュアル > ライブラリ一覧 > csvライブラリ > CSV::Tableクラス > by_row
by_row -> CSV::Table
Returns a duplicate table object, in row mode. This is handy for chaining in a single call without changing the table mode, but be aware that this method can consume a fair amount of memory for bigger data sets.
This method returns the duplicate table for chaining. Don't chain destructive methods (like []=()) this way though, since you are working with a duplicate.