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object-scanvsjmespath

MIT 15 8 157
138.2 thousand (month) Jun 10 2018 19.0.5(5 months ago)
2,053 2 55 MIT
1.0.1(1 year, 9 months ago) Feb 09 2022 179.6 million (month)

object-scan allows traversal of complex javascript objects to find specific keys.

In web scraping, it's useful for parsing large, nested JSON datasets for specific datafields. object-scan can be used to recursively find any key in any object structure:

import objectScan from 'object-scan';

const haystack = { a: { b: { c: 'd' }, e: { f: 'g' } } };
objectScan(['a.*.f'], { joined: true })(haystack);
// => [ 'a.e.f' ]

JMESPath (pronounced “james path”) allows you to declaratively specify how to extract elements from a JSON document.

In web scraping, jmespath is a powerful tool for parsing and reshaping large JSON datasets. Jmespath is fast and easily extendible following it's own powerful query language.

For more see the Json parsing introduction section.

Example Use


const objectScan = require('object-scan');

const myNestedObject = {
  level1: {
    level2: {
      level3: {
        myTargetKey: 'value',
      },
    },
  },
};

const searchTerm = 'myTargetKey';
const result = objectScan([`**.${searchTerm}`], { joined: false })(myNestedObject);
console.log(result);
import jmespath

data = {
    "data": {
        "info": {
            "products": [
                {"price": {"usd": 1}, "_type": "product", "id": "123"}, 
                {"price": {"usd": 2}, "_type": "product", "id": "345"}
            ]
        }
    }
}

# easily reshape nested dataset to flat structure:
jmespath.search("data.info.products[*].{id:id, price:price.usd}", data)
[{'id': '123', 'price': 1}, {'id': '345', 'price': 2}]

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