从ruby中的哈希数组打印表到文件

我想把以下数组作为表输出到file.txt。

arr=[{:food=>"", :calories=>"Calories", :carbs=>"Carbs", :fat=>"Fat", :protein=>"Protein", :cholest=>"Sodium"}, {:food=>"New York Bagel Co - Wholemeal Bagels*, 90 g bagel", :calories=>"223", :fat=>"2", :protein=>"9", :cholest=>"360"}, {:food=>"Nescafe - Decaf Coffee With Semi Skimmed Milk, 1 mug", :calories=>"12", :fat=>"0", :protein=>"1", :cholest=>"0"}, {:food=>"", :calories=>"235", :fat=>"2", :protein=>"10", :cholest=>"360"}] 

我想要的结果是：

 Food Calories Fat Protein Cholest New York Bagel Co - Wholemeal Bagels*, 90 g bagel 223 2 9 360 Nescafe - Decaf Coffee With Semi Skimmed Milk, 1 mug 12 0 1 0 235 2 10 360 

如果我能让Markdown获得更好的标题:-)

许多TIA

Answer 1

 @col_width = arr.inject(Hash.new(0)) do |col_width, h| h.each{|k, v| col_width[k] = [col_width[k], v.length].max} col_width end arr.each do |h| puts h.map do |k, v| v.send(case k; when :food; :ljust else :rjust end, @col_width[k]) end.join(" ") end