[GIS] Dynamically creating lyr file in ArcPy (for use with group layer)

arcpygroup-layerlayer-file

I'm trying to create an mxd that can dynamically create and name group layers, and populate them with various feature layers. I've seen some examples of how to do this, such as : Creating empty group layer within existing group layer using arcpy.mapping?

The basics seem to be: reference an empty layer file:

groupLayer = arcpy.mapping.Layer(r"D:\Test\GroupTest.lyr")

Add it to the map:

arcpy.mapping.AddLayer(df, groupLayer, "BOTTOM")
listedGroupLayer = arcpy.mapping.ListLayers(mxd, "GroupTest", df)[0]

Then add some layer to it:

addLayer = arcpy.mapping.layer(r"D\Test\Rivers.lyr")
arcpy.mapping.AddLayerToGroup(df, listedGroupLayer, addLayer, "BOTTOM")[0]

I'm getting stuck on the first step: I need to dynamically create an empty layer file (based off of group layer names in a spreadsheet), before referencing it.

Any examples of how to create an empty layer file (rather than reference one), within python?

Best Answer

Another option is to have a generic group layer saved as *.lyr file. Then when you load the layer change the name property and add it to the map document. You may be able to rename it after adding it to the map document. Then save the map document to retain the changes.

lyr = arcpy.mapping.Layer("grouplayer.lyr")
lyr.name = "Test Name"
mxd = arcpy.mapping.MapDocument("CURRENT")
df = arcpy.mapping.ListDataFrames(mxd)[0]
arcpy.mapping.AddLayer(df,lyr,"BOTTOM")

Related Solutions

Arcpy – How to Create Empty Group Layer Within Existing Group Layer in ArcGIS 10.1

Typo in your code. Should be:

targetGroupLayer = arcpy.mapping.ListLayers(mxd, "Group", df)[0]

otherwise targetGroupLayer is a list.

[GIS] Adding group layer, renaming it from folder name, then adding layers to it from that folder, using ArcPy/Python

This should work; it worked for me. This will give you a group layer named by the folder and a layer with the name of the shapefile. I built off what artwork21 posted.

import os
import arcpy

WS = r'c:\test_define'
arcpy.env.workspace = "in_memory"

mxd = arcpy.mapping.MapDocument(r"c:\test_define\test_python_add2.mxd")
df = arcpy.mapping.ListDataFrames(mxd, "Layers")[0]

for (path, dirs, files) in os.walk(WS):
    for name in files:
        if name.endswith(".shp"):

            groupLayer = arcpy.mapping.Layer(r"c:\test_define\empty_group_layer.lyr")  
            arcpy.mapping.AddLayer(df, groupLayer, "BOTTOM")

            layers = arcpy.mapping.ListLayers(mxd)
            for layer in layers:
                if layer.isGroupLayer and layer.name == "New Group Layer":
                    layer.name = os.path.basename(path)

            newLayer = arcpy.mapping.Layer(os.path.join(path, name))
            arcpy.mapping.AddLayerToGroup(df, layer, newLayer, "BOTTOM")

mxd.save()

You have to make the shapefiles into layers and use AddLayerToGroup. If you want a single group layer for each folder you can recycle this code and modify the os.walk to check for folders with .shp's and go from there. Although, I would recommend trying to contain all these shapefiles into a geodatabase with a proper naming structure and metadata to fit your needs.

To elaborate on the nonrepeating,

import arcpy
import os 

WS = r'c:\test_define'
arcpy.env.workspace = "WS"
mxd = arcpy.mapping.MapDocument(r"c:\test_define\test_python_add2.mxd")
df = arcpy.mapping.ListDataFrames(mxd, "Layers")[0]
groupLayer = arcpy.mapping.Layer(r"c:\test_define\empty_group_layer.lyr")

for (path, dirs, files) in os.walk(WS):
    for name in files:
        if name.endswith(".shp"):

            layers = arcpy.mapping.ListLayers(mxd)
            name_list = []
            for layer in layers:
                if layer.isGroupLayer:
                    name_list.append(layer.name)

            if os.path.basename(path) not in name_list:
                arcpy.mapping.AddLayer(df, groupLayer, "BOTTOM")
                layers = arcpy.mapping.ListLayers(mxd)
                for layer in layers:
                    if layer.isGroupLayer and layer.name == "New Group Layer":
                        layer.name = os.path.basename(path)
                        newLayer = arcpy.mapping.Layer(os.path.join(path, name))
                        arcpy.mapping.AddLayerToGroup(df, layer, newLayer, "BOTTOM")

            if os.path.basename(path) in name_list:
                layers = arcpy.mapping.ListLayers(mxd)
                for layer in layers:
                    if layer.isGroupLayer and layer.name == os.path.basename(path):
                        newLayer = arcpy.mapping.Layer(os.path.join(path, name))
                        arcpy.mapping.AddLayerToGroup(df, layer, newLayer, "BOTTOM")


mxd.save()

This will check to see if a group layer already exists and will add to it, if so. Else, it will create a new group layer and add the layer.

Best Answer

Related Solutions

Arcpy – How to Create Empty Group Layer Within Existing Group Layer in ArcGIS 10.1

[GIS] Adding group layer, renaming it from folder name, then adding layers to it from that folder, using ArcPy/Python

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