Depth first recursive versions of Hash::except

hash_extensions.rb

class Hash
  def except_nested(key)
    r = Marshal.load(Marshal.dump(self))
    r.except_nested!(key)
  end
  
  def except_nested!(key)
    self.except!(key)
    self.each do |_, v|
      v.except_nested!(key) if v.is_a?(Hash)
    end
  end
end

In the case that removing keys inside array is needed:

class Hash
  def except_nested(key)
    r = Marshal.load(Marshal.dump(self))
    r.except_nested!(key)
  end

  def except_nested!(key)
    self.reject!{|k, v|k == key}
    self.each do |_, v|
      v.except_nested!(key) if v.is_a?(Hash)
      v.map!{|obj| obj.except_nested!(key) if obj.is_a?(Hash)} if v.is_a?(Array)
    end
  end
end

The except! was replaced by reject, since the first is exclusive for newer ruby verions.