What is the best way to store scraped data from Ruby?

Storing scraped data in Ruby can be done in several ways depending on the scale of your data, the nature of your application, and how you intend to use the data. Below are some commonly used methods for storing scraped data:

1. CSV Files

For small to medium-sized data, CSV (Comma-Separated Values) files are a simple and convenient choice. They can be easily read and written using Ruby's CSV library and imported into spreadsheet programs like Microsoft Excel or Google Sheets.

require 'csv'

# Assuming `scraped_data` is an array of hashes
scraped_data = [
  { name: 'Product 1', price: 10.99, stock: 20 },
  { name: 'Product 2', price: 15.49, stock: 35 }
]

CSV.open('scraped_data.csv', 'wb', headers: scraped_data.first.keys, write_headers: true) do |csv|
  scraped_data.each do |row|
    csv << row.values
  end
end

2. JSON Files

JSON (JavaScript Object Notation) files are also a great option, especially if the data needs to be consumed by a web service or application. Ruby's JSON library can be used to read and write JSON data.

require 'json'

scraped_data = [
  { name: 'Product 1', price: 10.99, stock: 20 },
  { name: 'Product 2', price: 15.49, stock: 35 }
]

File.open('scraped_data.json', 'w') do |file|
  file.write(scraped_data.to_json)
end

3. Databases

For larger datasets or when you need to perform complex queries, using a database is the best option. Ruby has libraries for interfacing with all major databases, such as SQLite, PostgreSQL, and MySQL.

SQLite Example

require 'sqlite3'

# Create or open the database
db = SQLite3::Database.new 'scraped_data.db'

# Create a table
db.execute <<-SQL
  CREATE TABLE IF NOT EXISTS products (
    id INTEGER PRIMARY KEY,
    name TEXT,
    price REAL,
    stock INTEGER
  );
SQL

# Insert data
scraped_data.each do |product|
  db.execute("INSERT INTO products (name, price, stock) VALUES (?, ?, ?)", product[:name], product[:price], product[:stock])
end

4. Object-Relational Mapping (ORM)

ORM libraries like ActiveRecord (used in Ruby on Rails) or Sequel can help manage database interactions in a more Ruby-esque way.

Sequel Example

require 'sequel'

# Connect to the database
DB = Sequel.connect('sqlite://scraped_data.db')

# Create a dataset
products = DB[:products]
products.insert_conflict.insert(name: 'Product 1', price: 10.99, stock: 20)
products.insert_conflict.insert(name: 'Product 2', price: 15.49, stock: 35)

# Query the dataset
products.where(price: 10.99).all

5. Key-Value Stores

If your data has a simple structure and you need fast read and write operations, you might consider a key-value store like Redis.

require 'redis'

redis = Redis.new

scraped_data.each_with_index do |product, index|
  redis.set("product:#{index}", product.to_json)
end

6. Document-Based Databases

For flexible schema and complex data structures, document-based databases like MongoDB are suitable. There are Ruby libraries like mongo that provide an interface to MongoDB.

require 'mongo'

client = Mongo::Client.new(['127.0.0.1:27017'], database: 'scraped_data')
collection = client[:products]

scraped_data.each do |product|
  collection.insert_one(product)
end

Conclusion

The best way to store scraped data in Ruby depends on the particular requirements of your project. For simplicity and small datasets, CSV or JSON files might suffice. For larger datasets, more complex querying, or high-performance applications, a database (relational or NoSQL) would be more appropriate. Evaluate your project's needs and choose the storage method that provides the right balance of simplicity, performance, and features.