What are a few ways constants and enums are dealt with when creating an API Client?  I'm writing a client in python for our API and I've hit a sticking point with this.  We use a lot of mappings to numbers (to save space) and I was wondering what the best technique is.  I can hard code them into the client, but if a new enum/constant gets added, the consumer would have to update his version of the client.  I also thought about grabbing the maps/enums when the client is first initialized and cached until there is an update.  Are these typical approaches, or is there a more effective way to do this?