Where to put the extension methods(loaded only once) in rails application

I开发者_高级运维 have couple of helper methods added to the existing classes, and i want them to be loaded only once. for example i have a except method

class Array
  def except(array)
    self.select do |item|
      array.exclude? item
    end
  end
end

and would like to call it from different views & controllers like this

 a= [1,2,3,4]
 b=a.except [1,3]

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Put it into a file in config/initializers. These are loaded in alphabetic order; so if some other code uses it during initialisation, just use a file like config/initializers/000_important_monkey_patches.rb