JavaScript - 基于空单元格对 CSV 字段进行分组

Question

我有来自 CSV 文件的数据，该文件可以包含空白字段，并且必须基于该字段对数据进行分组。

这是一个按位置划分的人员数据的简单示例。位置数据仅针对第一个人显示，并且每个未分配位置的后续人员都属于之前的位置：

"Objects:", [{
    location: "New York",
    date: "10/10/2021",
    name: "Max",
    surname: "Payne"
}, {
    location: "",
    date: "",
    name: "Duke",
    surname: "Nuken"
}, {
    location: "",
    date: "",
    name: "Jack",
    surname: "Carver"
}, {
    location: "Las Vegas",
    date: "30/10/2021",
    name: "Leon",
    surname: "Kennedy"
}, {
    location: "",
    date: "",
    name: "Donkey",
    surname: "Kong"
}, {
    location: "",
    date: "",
    name: "Ryu",
    surname: "Hayabusa"
}]

我需要将人员列表加入一个列表并添加到相应的位置：

"Objects:", [{
    location: "New York",
    date: "10/10/2021",
    persons: [{
        name: "Max",
        surname: "Payne"
    }, {
        name: "Duke",
        surname: "Nuken"
    }, {
        name: "Jack",
        surname: "Carver"
    }]
}, {
    location: "Las Vegas",
    date: "30/10/2021",
    persons: [{
        name: "Leon",
        surname: "Kennedy"
    }, {
        name: "Donkey",
        surname: "Kong"
    }, {
        name: "Ryu",
        surname: "Hayabusa"
    }]
}]

数据最初是以这种形式作为数组的数组来的：

const [headers, ...lines] = [
    ["location",  "date",       "name",   "surname" ],
    ["New York",  "10/10/2021", "Max",    "Payne"   ],
    ["",          "",           "Duke",   "Nuken"   ],
    ["",          "",           "Jack",   "Carver"  ],
    ["Las Vegas", "30/10/2021", "Leon",   "Kennedy" ],
    ["",          "",           "Donkey", "Kong"    ],
    ["",          "",           "Ryu",    "Hayabusa"],
];

我目前必须将数组转换为这个问题的第一个对象列表的代码是这样的：

const locations = lines.map( (line) =>
   line.reduce((object, value, index) =>
        ({...object, [ headers[index] ]: value})
      , {}
   ));

什么是解决这个问题的好方法？

Answer 1

这是一个使用Array#reduce() 并对标题名称进行硬编码的示例。

const
  [headers, ...lines] = [["location", "date", "name", "surname"], ["New York", "10/10/2021", "Max", "Payne"], ["", "", "Duke", "Nuken"], ["", "", "Jack", "Carver"], ["Las Vegas", "30/10/2021", "Leon", "Kennedy"], ["", "", "Donkey", "Kong"], ["", "", "Ryu", "Hayabusa"],],

  result = lines.reduce((a, [location, date, name, surname]) => {
    if (location && date) a.push({ location, date, persons: [] });

    a[a.length - 1].persons.push({ name, surname });

    return a;
  }, []);

console.log(JSON.stringify(result, null, 2));

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这里是一个更动态的示例，允许您指定应该呈现给分组依据的“requiredIndeces”。您可以根据自己的特定需求进行调整。

const
  input = [["location", "date", "name", "surname"], ["New York", "10/10/2021", "Max", "Payne"], ["", "", "Duke", "Nuken"], ["", "", "Jack", "Carver"], ["Las Vegas", "30/10/2021", "Leon", "Kennedy"], ["", "", "Donkey", "Kong"], ["", "", "Ryu", "Hayabusa"],],

  refactorCSV = (arr, requiredIndeces) => {
    const
      reduceByRequiredIndex = (arr) => arr.reduce((a, x, i) =>
        (a[+requiredIndeces.includes(i)].push(x), a), [[], []]),
      [headers, ...lines] = arr,
      [entryProps, requiredProps] = reduceByRequiredIndex(headers);

    return lines.reduce((a, line) => {
      const [personValues, requiredValues] = reduceByRequiredIndex(line);

      if (requiredValues.every(v => v !== '')) {
        const required = {};
        requiredProps.forEach((prop, i) => required[prop] = requiredValues[i]);

        a.push({ ...required, persons: [] });
      }

      const person = {};
      entryProps.forEach((prop, i) => person[prop] = personValues[i]);

      a[a.length - 1].persons.push(person);

      return a;
    }, []);
  },

  result = refactorCSV(input, [0, 1]);

console.log(JSON.stringify(result, null, 2));

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