person_parser.rb

require 'csv'

# ["id", "first_name", "last_name", "email", "phone", "created_at"]
class Person
  attr_reader :first_name, :last_name, :email
  def initialize(attributes)
    @id = attributes["id"]
    @first_name = attributes["first_name"]
    @last_name = attributes["last_name"]
    @email = attributes["email"]
    @phone = attributes["phone"]
  end

  def to_a
    [self.first_name, self.last_name, self.email]
  end
  # Look at the above CSV file
  # What attributes should a Person object have?
end

class PersonParser
  attr_reader :file

  def initialize(file, save_file)
    @file = file
    @people = []
    @save_file = save_file
  end

  def people
    return @people if @people
    CSV.foreach(@file, {:headers => true}) do |row|
      @people << Person.new(row)
    end
  end

  def save_to_csv
    CSV.open(@save_file, 'w') do |csv|
      people.each do |person|
        csv << person.to_a
      end
    end
  end

end

parser = PersonParser.new('people.csv', 'erik_and_ted_and_crew.csv')

puts "There are #{parser.people.size} people in the file '#{parser.file}'."
parser.save_to_csv