CODEWITHSUNDEEP
jsonrubyparsing
Sookie J
Sookie J

Reputation: 893

Parsing from a JSON file in Ruby and Extract numbers from Nested Hashes

Now I am working on extracting information from a JSON file in Ruby. Then how can I extract just the numbers next to the word 'score' from the following text file? For example, I want to get 0.6748984055823062, 0.6280145725181376 on and on.

{
  "sentiment_analysis": [
    {
      "positive": [
        {
          "sentiment": "Popular",
          "topic": "games",
          "score": 0.6748984055823062,
          "original_text": "Popular games",
          "original_length": 13,
          "normalized_text": "Popular games",
          "normalized_length": 13,
          "offset": 0
        },
        {
          "sentiment": "engaging",
          "topic": "pop culture-inspired games",
          "score": 0.6280145725181376,
          "original_text": "engaging pop culture-inspired games",
          "original_length": 35,
          "normalized_text": "engaging pop culture-inspired games",
          "normalized_length": 35,
          "offset": 370
        },
     "negative": [
    {
      "sentiment": "get sucked into",
      "topic": "the idea of planning",
      "score": -0.7923352042939829,
      "original_text": "Students get sucked into the idea of planning",
      "original_length": 45,
      "normalized_text": "Students get sucked into the idea of planning",
      "normalized_length": 45,
      "offset": 342
    },
    {
      "sentiment": "be daunted",
      "topic": null,
      "score": -0.5734506634410159,
      "original_text": "initially be daunted",
      "original_length": 20,
      "normalized_text": "initially be daunted",
      "normalized_length": 20,
      "offset": 2104
    },

What I have tried is that I could read a file and set the text file to a hash variable using the JSON method.

require 'json'
json = JSON.parse(json_string)

Upvotes: 50

Views: 77221

Answers (3)

Blair Anderson
Blair Anderson

Reputation: 20171

Parse Data from File:

data_hash = JSON.parse(File.read('file-name-to-be-read.json'))

Then just map over the data!

reviews = data_hash['sentiment_analysis'].first
reviews.map do |sentiment, reviews|
  puts "#{sentiment} #{reviews.map { |review| review['score'] }}"
end

I think this is the simplest answer.

Upvotes: 28

DexterHaxxor
DexterHaxxor

Reputation: 1005

Using the JSON class:

Importing a file:

require "json"
file = File.open "/path/to/your/file.json"
data = JSON.load file

Optionally, you can close it now:

file.close

The file looks like this:

{
  "title": "Facebook",
  "url": "https://www.facebook.com",
  "posts": [
    "lemon-car",
    "dead-memes"
  ]
}

The file is now able to be read like this:

data["title"]
=> "Facebook"
data.keys
=> ["title", "url", "posts"]
data['posts']
=> ["lemon-car", "dead-memes"]
data["url"]
=> "https://www.facebook.com"

Hope this helped!

Upvotes: 81

Arun Kumar Mohan
Arun Kumar Mohan

Reputation: 11915

You can use Array#map to collect the reviews.

reviews = json['sentiment_analysis'][0]
positive_reviews = reviews['positive']
negative_reviews = reviews['negative']

positive_reviews.map { |review| review['score'] }
=> [0.6748984055823062, 0.6280145725181376]

negative_reviews.map { |review| review['score'] }
=> [-0.7923352042939829, -0.5734506634410159]

Hope this helps!

Upvotes: 9

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