Ruby 更快的CSV+；试图找到独特的项目

我有一个csv文件，我试图找到第2列中的所有uniq值，其中第1列具有相同的值，并将其合并到一个新的csv文件中。我知道，这听起来很让人困惑，所以这里有一个例子：

原始文件foo.csv的示例：

"Boom Lifts","Model Number","Manufacturer","Platform Height","Horizontal Outreach","Lift Capacity"
"Boom Lifts","Model Number","Platform Height","Horizontal Outreach","Up & Over Height","Platform Capacity"
"Boom Lifts","Model Number","Platform Height","Horizontal Outreach","Up & Over Height"
"Pusharound Lifts","Model Number","Manufacturer","Platform Height","Stowed Height"
"Scissor Lifts","Model Number","Manufacturer","Platform Height","Stowed Height","Overall Dimensions","Platform Extension"
"Scissor Lifts","Overall Dimensions","Platform Size","Platform Extension","Lift Capacity"

理想结果栏.csv：

"Boom Lifts","Model Number","Manufacturer","Platform Height","Horizontal Outreach","Lift Capacity","Up & Over Height","Platform Capacity",,,
"Pusharound Lifts","Model Number","Manufacturer","Platform Height","Stowed Height"
"Scissor Lifts","Model Number","Manufacturer","Platform Height","Stowed Height","Overall Dimensions","Platform Size","Platform Extension","Lift Capacity"

每一行都有不同的长度，而且它是一个相当大的文件（超过5k行），我完全不知道如何进行匹配/字符串操作。是的，有些行后面有逗号，其中有“空单元格”。我一直在使用更快的CSV，所以如果有一种方法可以做到这一点，那就太好了

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指针？最好是一些不会让我的mbp突然停止的东西？

假设您可以将其放入具有更快CSV的2d阵列中：

a = [
  ["Boom Lifts","Model Number","Manufacturer","Platform Height","Horizontal Outreach","Lift Capacity"]
  ["Boom Lifts","Model Number","Platform Height","Horizontal Outreach","Up & Over Height","Platform Capacity"]
  ["Boom Lifts","Model Number","Platform Height","Horizontal Outreach","Up & Over Height"]
  ["Pusharound Lifts","Model Number","Manufacturer","Platform Height","Stowed Height"]
  ["Scissor Lifts","Model Number","Manufacturer","Platform Height","Stowed Height","Overall Dimensions","Platform Extension"]
  ["Scissor Lifts","Overall Dimensions","Platform Size","Platform Extension","Lift Capacity"]
]

a.group_by {|e| e[0]}.map {|e| e.flatten.uniq}

让你：

[
  ["Boom Lifts", "Model Number", "Manufacturer", "Platform Height", "Horizontal Outreach", "Lift Capacity", "Up & Over Height", "Platform Capacity"]
  ["Pusharound Lifts", "Model Number", "Manufacturer", "Platform Height", "Stowed Height"]
  ["Scissor Lifts", "Model Number", "Manufacturer", "Platform Height", "Stowed Height", "Overall Dimensions", "Platform Extension", "Platform Size", "Lift Capacity"]
]

---

不会是即时的，但不应降低MBP。

因此，a）第一列可以被视为键，b）所有后续列可以被视为列表中的值，最后您希望此列表包含唯一的值。。。？bar.csv中的最后一行重复“外形尺寸”和“平台扩展”。重复的值是否正常？我的错误、所有维度和平台扩展不应重复。我想用fasterCSV读入一个文件foo.csv，然后吐出另一个bar.csv。谢谢