title: How To Check If A Key in **kwargs Exists?
body: <p>Python 3.2.3. There were some ideas <a href="https://stackoverflow.com/questions/9390126/pythonic-way-to-check-if-something-exists">listed here</a>, which work on regular var's, but it seems **kwargs play by different rules... so why doesn't this work and how can I check to see if a key in **kwargs exists?</p>
  
  <pre><code>if kwargs['errormessage']:
      print("It exists")
  </code></pre>
  
  <p>I also think this should work, but it doesn't --</p>
  
  <pre><code>if errormessage in kwargs:
      print("yeah it's here")
  </code></pre>
  
  <p>I'm guessing because kwargs is iterable? Do I have to iterate through it just to check if a particular key is there?</p>