How to get the file path for layers within a group layer?

Question

I am trying to use python to remap a set of layer files in a group layer (not within an mxd) but am unable to create a layer object for them so I can use replaceDataSource. One of my group layers is

C:\Workspace\LayerFiles\Administration.lyr

I've attempted to use arcpy.mapping.Layer with the following paths:

C:\Workspace\LayerFiles\Administration.lyr\Ownership.lyr C:\Workspace\LayerFiles\Administration.lyr\Ownership C:\Workspace\LayerFiles\Administration\Ownership.lyr C:\Workspace\LayerFiles\Administration\Ownership

which all come up with ValueError: Object: CreateObject Layer invalid data source

Is there no way to get a direct path to layers within a group layer? If that's the case is there another means to create a layer object for each one within a loop? Hopefully there's a simple answer, but my search has come up empty so far.

Answer 1

There isn't a layer file within another layer file. It's just a layer object that contains multiple layer objects. The 'isGroupLayer' property tells you whether it is a group layer or not. You can iterate through them and change the source like so:

import arcpy

group_layer = arcpy.mapping.Layer('C:\\Workspace\\LayerFiles\\Administration.lyr')
for layer in group_layer:
    if layer.name == 'Ownership':
        layer.replaceDataSource('C:\\Path\\To\\New\\Source',
                                'SHAPEFILE_WORKSPACE', # Or whatever type of workspace
                                'New_Source')

# Overwrite the old layer file
group_layer.saveACopy('C:\\Workspace\\LayerFiles\\Administration.lyr')

Also, make sure you are using double backslashes on your file paths in Windows.