topic Re: arcpy: get access to layer that's in group layer? in Python Questions

arcpy: get access to layer that's in group layer?

helenchu — Fri, 21 Sep 2018 15:16:23 GMT

I created a model builder and scripted it out to python. My issue is it only works if the layer is outside of group layer. How can I modify it to works in both inside and outside of group layer? Thank you very much for your help.

import arcpy,sys, os
arcpy.env.overwriteOutput = True
arcpy.env.workspace = r"C:\GIS\MyGeodatabase.gdb"
mxd = arcpy.mapping.MapDocument("CURRENT")
layerName = 'street'
lyr = arcpy.mapping.ListLayers(mxd, layerName)[0]
fc = arcpy.GetParameterAsText(0)

Street = "Street"

selCount = 0
if lyr.getSelectionSet(): # If there are selected features
selCount = len(lyr.getSelectionSet())
arcpy.AddMessage("{0} has {1} features selected.".format(fc, selCount))
try:
# Process: Copy Features
arcpy.CopyFeatures_management(Street , street_CopySelected, "", "0", "0", "0")

Re: arcpy: get access to layer that's in group layer?

JoshuaBixby — Fri, 21 Sep 2018 16:16:09 GMT

Saying something "doesn't work" often isn't specific enough for people to offer much feedback. Does it generate an error when run within a group layer? If so, what is the error, including the trace back. Or, does it give unexpected results? If so, what are you expecting and what are you seeing?

Re: arcpy: get access to layer that's in group layer?

helenchu — Fri, 21 Sep 2018 16:25:57 GMT

It just doesn't find that layerName so the script did nothing. Thanks.

Re: arcpy: get access to layer that's in group layer?

JoshuaBixby — Fri, 10 Dec 2021 20:30:19 GMT

When the layer is nested under a group layer, what does the following code give for results:

mxd = arcpy.mapping.MapDocument("CURRENT")
for lyr in arcpy.mapping.ListLayers(mxd):
    print lyr.longName‍‍‍

Re: arcpy: get access to layer that's in group layer?

RandyBurton — Fri, 10 Dec 2021 20:30:22 GMT

You may have some issues with how you are using getSelectionSet. My test code:

mxd = arcpy.mapping.MapDocument("CURRENT")
layerName = 'street'
lyr = arcpy.mapping.ListLayers(mxd, layerName)[0]
for l in lyr:
    print l.name, l.getSelectionSet(), len(l.getSelectionSet()) if l.getSelectionSet() is not None else 'None'

    #  and if you only want to work with layer named 'street'
    if l.name == 'street':
        # do something‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍

Re: arcpy: get access to layer that's in group layer?

helenchu — Fri, 21 Sep 2018 17:27:52 GMT

TopLayerGroup\Street

I replaced Street = lyr.longName and it still does not work. It gives my the selection count but not doing the copy features. Thanks.

My code looks like this:

df = arcpy.mapping.ListDataFrames(mxd)[0]
for lyr in arcpy.mapping.ListLayers(mxd,"",df): #loop layers
if lyr.name == "Street":
Street= lyr.longName
selCount = 0
selCount = len(lyr.getSelectionSet())
arcpy.AddMessage("{1} features selected.".format(fc, selCount))
try:
# Process: Copy Features
arcpy.CopyFeatures_management(lyr.Street, street_CopySelected, "", "0", "0", "0")
del df

except Exception as e:
print e.args[0]

Re: arcpy: get access to layer that's in group layer?

RandyBurton — Fri, 21 Sep 2018 17:33:38 GMT

Can you post a screenshot of how your layers are organized?

Also, it helps to see formatted code: Code Formatting... the basics++

Re: arcpy: get access to layer that's in group layer?

JoshuaBixby — Fri, 21 Sep 2018 17:44:34 GMT

Python is case sensitive, i.e., "Street" != "street". In your original code, you are using both. Trying being consistent with your case.

Re: arcpy: get access to layer that's in group layer?

RandyBurton — Fri, 10 Dec 2021 20:30:25 GMT

You might try something like:

import arcpy,sys, os
arcpy.env.overwriteOutput = True
arcpy.env.workspace = r"C:\GIS\MyGeodatabase.gdb"
mxd = arcpy.mapping.MapDocument("CURRENT")

layerName = 'street'

for lyr in arcpy.mapping.ListLayers(mxd, layerName)[0]:
    if lyr.getSelectionSet(): # If there are selected features
        arcpy.AddMessage("{} has {} features selected".format(lyr.name, len(lyr.getSelectionSet()))

        # Process: Copy Features
        arcpy.CopyFeatures_management(Street , street_CopySelected, "", "0", "0", "0")
‍‍‍‍‍‍‍‍‍‍‍‍‍

Re: arcpy: get access to layer that's in group layer?

helenchu — Fri, 21 Sep 2018 18:12:29 GMT

Re: arcpy: get access to layer that's in group layer?

helenchu — Fri, 21 Sep 2018 18:15:19 GMT

Thanks for the tip! When I drag my Street layer out of TopLayerGroup, the codes work just fine. I begin to suspect if group layer is supported by ESRI for doing most of data management tools?

Re: arcpy: get access to layer that's in group layer?

helenchu — Fri, 10 Dec 2021 20:30:28 GMT

# Import arcpy module
import arcpy,sys, os
arcpy.env.overwriteOutput = True
arcpy.env.workspace = r"C:\GIS\MyGeodatabase.mdb"
mxd = arcpy.mapping.MapDocument("CURRENT")
layerName = 'Street'
lyr = arcpy.mapping.ListLayers(mxd, layerName)[0]
fc = arcpy.GetParameterAsText(0)



Street = "Street"
street_CopySelected = "street_CopySelected"


df = arcpy.mapping.ListDataFrames(mxd)[0]
for lyr in arcpy.mapping.ListLayers(mxd,"",df):     #loop layers

          if lyr.name == "Street":
            arcpy.AddMessage("name: " + lyr.longName)
            layerName = lyr.longName
            Street = lyr.longName
            selCount = len(lyr.getSelectionSet())
            arcpy.AddMessage("{1} features selected.".format(fc, selCount))
            try:
                # Process: Copy Features
                arcpy.CopyFeatures_management(Street, street_CopySelected, "", "0", "0", "0")
                del df

            except Exception as e:
                print e.args[0]‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍

Re: arcpy: get access to layer that's in group layer?

helenchu — Fri, 21 Sep 2018 19:32:17 GMT

Randy,

I tried your codes and they did not work for me. Thanks.

Error:

Traceback (most recent call last):
File "C:\Working\Python\python_script\copy_test_1.py", line 9, in <module>
for lyr in arcpy.mapping.ListLayers(mxd, layerName)[0]:
File "c:\program files (x86)\arcgis\desktop10.6\arcpy\arcpy\arcobjects\mixins.py", line 401, in __iter__
self.layers
AttributeError: LayerObject: Get attribute layers does not exist

Re: arcpy: get access to layer that's in group layer?

RandyBurton — Fri, 10 Dec 2021 20:30:30 GMT

Thanks for formatting. It helps to see the indentation.

Regarding line 23:

selCount = len(lyr.getSelectionSet())‍‍

If lyr.getSelectionSet() == None, then len will return an error. You might want to check first:

if lyr.getSelectionSet():
    selCount = len(lyr.getSelectionSet())
    # do other things with the layer selection‍‍‍‍

Since you are using MapDocument("CURRENT"), are you planning to only use the tool inside ArcMap?

Re: arcpy: get access to layer that's in group layer?

RandyBurton — Fri, 10 Dec 2021 20:30:33 GMT

Try this change:

layerName = 'Street'

for lyr in arcpy.mapping.ListLayers(mxd, layerName): # remove [0]‍‍‍

Re: arcpy: get access to layer that's in group layer?

helenchu — Fri, 21 Sep 2018 21:06:04 GMT

I called ESRI support and the solution is

arcpy.CopyFeatures_management(lyr, street_CopySelected, "", "0", "0", "0")

It can not read the longName but it could read the object lyr.

Thank you all so much for your help.