title: NoMethodError: undefined method `except' for Hash
body: <p>While using except on Hash in Ruby,</p>
  
  <pre><code>d = {}
  d["a"]=1234
  d["b"]=34 
  d["c"]=3 
  d.except(:b,:c)
  </code></pre>
  
  <p>I am getting NoMethodError:</p>
  
  <pre><code>NoMethodError: undefined method `except' for {"a"=&gt;1234, "b"=&gt;34, "c"=&gt;3}:Hash  from (irb):6    from
  /Users/niranjan/.rvm/rubies/ruby-1.9.3-p551/bin/irb:12:in `&lt;main&gt;'
  </code></pre>
  
  <p>What am I doing wrong?</p>