In ArcMap under "layer properities", there is a menu option to "Match to symbols in a style" (i.e. "Layer Properties" -> "Symbology" -> "Categories" -> "Match to symbols in a style"). Is there any way to do the same thing using a python script?
The best way to find out is to explore the Arcpy tree and examine the mapping module and the basic arcpy classes and functions. This is a handy reference for bookmarking and generally returns information quicker than searches.