except

Return a hash that includes everything but the given keys. This is useful for limiting a set of parameters to everything but a few known toggles:

@person.update_attributes(params[:person].except(:admin))

If the receiver responds to convert_key, the method is called on each of the arguments. This allows except to play nice with hashes with indifferent access for instance:

{:a => 1}.with_indifferent_access.except(:a)  # => {}
{:a => 1}.with_indifferent_access.except("a") # => {}