title: How to check and get Alexa slot value with Python ask sdk
body: <p>In my interaction model I defined a slot named <code>city</code> that is optional, not required, to fulfill an intent.</p>
  
  <p>I'm using the python ask sdk, so my handler is this:</p>
  
  <pre><code>class IntentHandler(RequestHandler):
      """
      Intent handler
      """
  
      def can_handle(self, handler_input):
          # type: (HandlerInput) -&gt; bool
          return is_request_type("IntentRequest")(handler_input) and \
                 is_intent_name("ExampleIntent")(handler_input)
  
      def handle(self, handler_input):
          # type: (HandlerInput) -&gt; Response
          access_token = handler_input.request_envelope.context.system.user.access_token
  
          if access_token is None:
              raise Exception("no access_token provided")
  
          speech = RESPONSE_MESSAGE_DEFAULT
          handler_input.response_builder.speak(speech)
  
      return handler_input.response_builder.response
  </code></pre>
  
  <p>How can I check if the slot was filled by the user and how can I get its value?</p>