How to copy layers between MXD's with arcpy?

Question

In ArcGIS I need to being able to have a couple of MXD documents open and copy-paste groups of layers from one MXD's table of contents to another with python script.

Is this possible and, if so, how?

Answer 1

This code snippet will copy all the group layers from a template mxd and put them in the currently opened MXD in ArcMap, then save the mxd

#assuming code being run in the python interpreter window in ArcMap, else give it a path to the mxd
mxd = arcpy.mapping.MapDocument("Current")
df = mxd.activeDataFrame

#mxd to copy the group layers from... give it the path to your mxd that has the layers
layerTemplateMXD = arcpy.mapping.MapDocument(r"path to mxd that has layers")
templatedf = layerTemplateMXD.activeDataFrame

for layer in templatedf:
    if layer.isGroupLayer:
        # add the group layer to the bottom to maintain the order from the template mxd
        arcpy.mapping.AddLayer(df,layer,"BOTTOM")

# save it now that you've added the other layers
mxd.save()

Answer 2

You can try this, it requires saving your layers out to a lyr file on disk before adding it to the second map.

In map one, run this code:

arcpy.SaveToLayerFile_management("yourlayerinmap", r'youroutputlocation')

In map two, run this code:

mxd = arcpy.mapping.MapDocument('CURRENT')
df = arcpy.mapping.ListDataFrames(mxd)[0]
layer = arcpy.mapping.Layer('youroutputlocation')
arcpy.mapping.AddLayer(df, layer)