I have limited expertise with Python.  

I need to create labels based on groups of attributes.  I've figured out a clumsy way to accomplish this but it involves 20 different annotation classes / SQL queries / label expressions, and I really hope there is a way to accomplish this more elegantly and efficiently, ideally with just 1 label expression.

My input data (which cannot be altered) is a feature class with 3 relevant fields (which I've made generic here).  

 - Codelist - numeric codes
 - Attribute1 - an attribute
 - Attribute2 - a second attribute

Codelist contains 100 numbers.  Groups of these numbers require one label - for example codes 1,3,35,7,8 would get the label "Christmas, Attribute1, Attribute2" on 3 separate lines.  Codes 2,9,34,100,54,22 would get the label "Easter, Attribute 1, Attribute2" on 3 separate lines.  Etc etc.

I can't figure out how to use an SQL-like 'if [CODELIST] in (1,3,35,7,8):' statement in the Python label expression builder.  

Is it possible?  

Am I approaching this the right way or is my first effort using multiple annotation classes and SQL queries the best way to do this after all?