AWS DynamoDB batch write (put) in Ruby, ideally use in Lambda

ddb_batch_put.rb

require 'aws-sdk-dynamodb'

# DynamoDB batch write (put) routine
# @param items [Array<Hash>] DynamoDB items to put
# @param table [String] DynamoDB table name
def ddb_batch_put(items, table)
  ddb = Aws::DynamoDB::Client.new
  batch = items.map { |item| {put_request: {item: item}} if Hash === item }
  batch.compact!
  puts "Batch write to: #{table}, #{batch.length} items."
  batch = {table => batch}
  while batch
    resp = ddb.batch_write_item({request_items: batch })
    if resp.unprocessed_items.length > 0
      batch = resp.unprocessed_items
      puts "Unprocessed: #{batch}"
    else
      batch = nil
      puts 'Batch write complete.'
    end
  end
  true
rescue => e
  puts "ddb_batch_put error: #{e.message}"
  puts e.backtrace.join("\n")
  false
end