title: Python exception for HTTP response codes
body: <p>I'd like to raise a Python-standard exception when an HTTP response code from querying an API is not 200, but what specific exception should I use? For now I raise an OSError:</p>
  
  <pre><code>if response.status_code != 200:
    raise OSError("Response " + str(response.status_code)
                    + ": " + response.content)
  </code></pre>
  
  <p>I'm aware of the <a href="https://docs.python.org/2/library/exceptions.html" rel="noreferrer">documentation for built-in exceptions</a>.</p>