Here is a quick refresher fromt the Arc GIS help page: When you open a map, Arc Map looks for the data referenced by each of the layers in the map.If Arc Map can’t find the data source for a particular layer, that layer won’t be drawn.For any related queries on these scripts please contact the script author.
For example, a feature layer supports a definition query whereas a raster layer does not, but a raster catalog does.
The properties allow you to identify or isolate the majority of layer types but not all layer types.
There are a few specialized layers and datasets that don't fall into one of these three categories: annotation subclasses, dimension features, network datasets, terrain datasets, topology datasets, and so on.
I’m not going to lie, I don’t like python, probably because I’m turning into my dad and slowly find myself finding things a little harder to learn….
I think being able to cope with C , C#, VBA, HTML, CSS, Ferranti Fbasica, Cobal & (My favourite) Sinclair Basic, should be enough for anyone, python just tips me over the edge.