Convert Amazon orders export JSON to CSV

convert_amazon_orders.rb

require 'json'
require 'csv'

# There are more, but these are the ones I care about
keys = [
  'Order Date',
  'Order ID',
  'Currency',
  'Unit Price',
  'Total Owed',
  'ASIN',
  'Quantity',
  'Product Name'
]

files = [
  'Retail.OrderHistory.1.json',
  'Retail.OrderHistory.2.json' # International orders
]

orders = files.map { |f| JSON.load(File.read(f)) }.flatten.sort { |a, b| b['Order Date'] <=> a['Order Date'] }
orders.each { |order| order['Order Date'].sub!('T', ' ').sub!(/(?:\.\d{3})?Z/, '') }

CSV.open('orders.csv', 'wb') do |csv|
  csv << keys
  orders.each do |order|
    csv << keys.map { |k| order[k] }
  end
end