topic Re: Cast Feature Layer to Layer in Arcpy/Pro in Python Questions

Cast Feature Layer to Layer in Arcpy/Pro

MikeMacRae — Wed, 05 May 2021 22:55:07 GMT

Hello all. I have a script I am updating from ArcGIS Desktop (Python 2) to ArcGIS Pro (Python 3). As part of the older script I would cast a feature class as a feature layer via MakeFeatureLayer_management and then I would further cast that feature layer to a Layer object to get access to the layer's properties:

arcpy.MakeFeatureLayer_management(fc, "lyr") lyr = arcpy.mapping.Layer("lyr")

It appears that the Pro version of arcpy doesn't actually have a layer object in the mapping (mp) module anymore. So, if I were to do something similar:

arcpy.MakeFeatureLayer_management(fc, "lyr") lyr = arcpy.mp.Layer("lyr")

which returns:

AttributeError: module 'arcpy.mp' has no attribute 'Layer'

I also tried:

arcpy.MakeFeatureLayer_management(fc, "lyr") lyr = arcpy.mp.LayerFile("lyr")

and threw the error:

ValueError: lyr

So, at the end of the day, I need to take a geodatabase feature class and somehow cast it as a layer in order to manipulate layer properties in arcpy for Pro. Any suggestion how I can do that. Points for avoiding saving the layer to disk.

Re: Cast Feature Layer to Layer in Arcpy/Pro

DanPatterson — Thu, 06 May 2021 00:00:48 GMT

See the code example. Your layer will have the name "lyr"

Layer—ArcGIS Pro | Documentation

a Layerfile is a *.lyr or *.lyrx on disk

LayerFile—ArcGIS Pro | Documentation

Re: Cast Feature Layer to Layer in Arcpy/Pro

mody_buchbinder — Thu, 06 May 2021 05:13:47 GMT

The best way I found to do it is to use arcpy.SaveToLayerFile_management on the feature layer into some temporary folder. Then use the lyrx that was created to create a arcpy.mp.LayerFile

Not very elegant but does the work and does not take too much time.

Have Fun

Re: Cast Feature Layer to Layer in Arcpy/Pro

Luke_Pinner — Thu, 06 May 2021 12:36:44 GMT

Just use the layer object returned by the MakeFeatureLayer result:

layer = arcpy.management.MakeFeatureLayer(fc, "lyr")[0] layer <arcpy._mp.Layer object at 0x0000023785BDD080> layer.name 'lyr'

I don't have access to Desktop/ArcMap to test if the `[0]` indexing works like it does in Pro, but you could have used something like the following in ArcMap instead of casting:

layer = arcpy.MakeFeatureLayer_management(fc, "lyr").getOutput(0)

Re: Cast Feature Layer to Layer in Arcpy/Pro

MikeMacRae — Thu, 06 May 2021 15:18:42 GMT

Hey Dan. I looked at the code examples before, however to get to a single layer, it appears that you have to list out the maps from a project and then list the layers out. The examples don't speak to casting directly to a layer object without listing them out from some source. For example in the Desktop help doc, example #1 on the second line, it shows how to grab a layerfile and cast it as directly as a layer object via arcpy.mapping.Layer.I find it odd that Pro arcpy does not have that layer object in the new mapping class.

Re: Cast Feature Layer to Layer in Arcpy/Pro

MikeMacRae — Thu, 06 May 2021 15:20:03 GMT

Thanks. Yes, so far that's the only way I can see doing this, at this point. It's not how I want to handle the data, so I'm hoping to avoid saving to disk.

Re: Cast Feature Layer to Layer in Arcpy/Pro

MikeMacRae — Thu, 06 May 2021 15:56:40 GMT

Thanks @Luke_Pinner I am forgetting the subtleties of the switch to Pro. I didn't realized there was a sub-module for 'management' now as opposed to direct calls to Data Management tools. i.e.

Desktop 10.x:

arcpy.MakeFeatureLayer_management

vs ArcGIS Pro:

arcpy.management.MakeFeatureLayer

And nice call on the indexing of the layer object too. That's not something I would have intuitively thought to do.

Cheers,

Mike

Re: Cast Feature Layer to Layer in Arcpy/Pro

DanPatterson — Thu, 06 May 2021 16:45:54 GMT

Mike

MakeFeatureLayer_management or arcpy.management.MakeFeatureLayer

both work in Pro

Re: Cast Feature Layer to Layer in Arcpy/Pro

Luke_Pinner — Thu, 06 May 2021 23:01:44 GMT

arcpy.subpackage.Tool and arcpy.Tool_subpackage works in both Pro and Desktop.

Re: Cast Feature Layer to Layer in Arcpy/Pro

DanPatterson — Thu, 06 May 2021 23:35:38 GMT

another example here

Re: Script stopped working properly with upgrade o... - Esri Community

All paths lead to the same destination

In fact, if one is interested in the scripts follow the trail for MakeFeatureLayer

Toolbox location

C:\...Install_Folder...\Resources\ArcToolBox\toolboxes

C:\...Install_Folder...\Resources\ArcToolBox\toolboxes\Data Management Tools.tbx\MakeFeatureLayer.tool

Script and function location

C:\...Install_Folder...\Resources\ArcPy\arcpy\management.py

Re: Cast Feature Layer to Layer in Arcpy/Pro

SamSzotkowski — Fri, 08 Jul 2022 22:20:24 GMT