Getting a list of layers in a map document
Frequently, one of the first steps in a geoprocessing script is to obtain a list of layers in the map document. Once obtained, your script may then cycle through each of the layers and perform some type of processing. The mapping module contains a ListLayers() function, which provides the capability of obtaining this list of layers. In this recipe, you will learn how to get a list of layers contained within a map document.
Getting ready
The arcpy.mapping module contains various list functions to return lists of layers, data frames, broken data sources, table views, and layout elements. These list functions normally function as the first step in a multistep process, in which the script needs to get one or more items from a list for further processing. Each of these list functions returns a Python list, which, as you know from earlier in the book, is a highly functional data structure for storing information.
Normally, the list functions are used as...
