How to write pseudo parameters in troposphere?
<p>I want to use the pseudo parameter for a TopicConfigurations topics. So that I can allow the selection of a arn. How can I write a pseudo parameter using troposphere? </p>

<p>Topic Configuration: <a href="http://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/aws-properties-s3-bucket-notificationconfig-topicconfig.html" rel="nofollow">http://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/aws-properties-s3-bucket-notificationconfig-topicconfig.html</a></p>

<p>Psuedo Parameter: <a href="http://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/pseudo-parameter-reference.html" rel="nofollow">http://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/pseudo-parameter-reference.html</a></p>