如何根据嵌套对象的commander值过滤大型JSON文件？

方法一：Python实现 #

如果JSON文件体积适中，可直接加载到内存处理：

import json

# 读取目标JSON文件
with open('your_cards.json', 'r', encoding='utf-8') as f:
    cards = json.load(f)

# 筛选符合条件的卡片
filtered_cards = {
    card_name: card_data
    for card_name, card_data in cards.items()
    if card_data.get('leadershipSkills', {}).get('commander') is True
}

# 将筛选结果写入新文件
with open('filtered_commander_cards.json', 'w', encoding='utf-8') as f:
    json.dump(filtered_cards, f, indent=2)

若文件为GB级超大体积，建议用流式解析避免内存溢出：

import json

filtered_cards = {}
with open('your_cards.json', 'r', encoding='utf-8') as f:
    data = json.load(f)
    for card_name, card_data in data.items():
        if card_data.get('leadershipSkills', {}).get('commander') is True:
            filtered_cards[card_name] = card_data

# 保存筛选结果
with open('filtered_commander_cards.json', 'w', encoding='utf-8') as f:
    json.dump(filtered_cards, f, indent=2)

方法二：Node.js实现 #

常规体积文件处理：

const fs = require('fs');
// 若JSON含注释用jsonc-parser解析，无注释可直接用JSON.parse
const { parse } = require('jsonc-parser');

// 读取并解析文件
const rawData = fs.readFileSync('your_cards.json', 'utf8');
const cards = parse(rawData);

// 筛选符合条件的卡片
const filteredCards = Object.entries(cards).reduce((acc, [cardName, cardData]) => {
  if (cardData.leadershipSkills?.commander === true) {
    acc[cardName] = cardData;
  }
  return acc;
}, {});

// 写入结果文件
fs.writeFileSync('filtered_commander_cards.json', JSON.stringify(filteredCards, null, 2), 'utf8');

超大文件流式处理（需安装stream-json库）：

const { parser } = require('stream-json');
const { streamValues } = require('stream-json/streamers/StreamValues');
const fs = require('fs');
const { Writable } = require('stream');

const filteredCards = {};

const pipeline = fs.createReadStream('your_cards.json')
  .pipe(parser())
  .pipe(streamValues())
  .pipe(new Writable({
    objectMode: true,
    write({ key, value }, _, callback) {
      if (value.leadershipSkills?.commander === true) {
        filteredCards[key] = value;
      }
      callback();
    }
  }));

pipeline.on('finish', () => {
  fs.writeFileSync('filtered_commander_cards.json', JSON.stringify(filteredCards, null, 2), 'utf8');
});

内容的提问来源于stack exchange，提问作者Alexa Aria