How do I add a layer in the 'memory' workspace to the current active map in ArcGIS Pro using Python

[MattHowe]

According to the ArcGIS Pro support pages, "You can add memory datasets to a map in ArcGIS Pro.".

I have a layer in the 'memory' workspace that I would like to add to my current active map.  I've tried:

mem_lyr = r"memory\Test_Layer"
aprx = arcpy.mp.ArcGISProject("CURRENT")
aprx_map = aprx.activeMap
aprx_map.addDataFromPath(mem_lyr)

but get the below error. Is there a correct way to add layers in memory to the current map?

Traceback (most recent call last):
  File "<string>", line 1, in <module>
  File "C:\Program Files\ArcGIS\Pro\Resources\ArcPy\arcpy\_mp.py", line 1862, in addDataFromPath
    return convertArcObjectToPythonObject(self._arc_object.addDataFromPath(*gp_fixargs((data_path,), True)))
RuntimeError

[JoshuaBixby]

Most ArcPy functions and GP tools understand the "memory" and "in_memory" aliases, but not all of them.  The addDataFromPath method of the ArcPy Map object does not understand or honor it.

I suggest changing your workflow to start with Make Feature Layer (Data Management)—ArcGIS Pro | Documentation and then use addLayer method of Map—ArcGIS Pro | Documentation.

[MattHowe]

Thanks Joshua. Unfortunately I get the same error. I'll contact Esri support.

[JoeBorgione]

@MattHowe ; can you tell us what version of arcgis pro you are using? 

[MattHowe]

@JoeBorgione  sure, I'm using 2.7.2

[MatthewDriscoll]

Still does not work in 2.9.3 - Copy Features works but not Make Feature Layer. 

Code runs fine in 2.4.2.

Code runs fine in 2.9.3 when ran in the interactive widow.  If fails when run in a Toolbox.  

Tempcopy = arcpy.CopyFeatures_management(ParOrionLayer, "memory/tempParReg")

arcpy.MakeFeatureLayer_management(Tempcopy, "memory/tempO")

Traceback (most recent call last):
  File "<string>", line 91, in execute
  File "C:\Program Files\ArcGIS\Pro\Resources\ArcPy\arcpy\__init__.py", line 1287, in Describe
    return gp.describe(value, data_type)
  File "C:\Program Files\ArcGIS\Pro\Resources\ArcPy\arcpy\geoprocessing\_base.py", line 384, in describe
    self._gp.Describe(*gp_fixargs(args, True)))
OSError: "memory/tempO" does not exist

Failed to execute (PDFTool).

With addLayer

ParOTempcopy = arcpy.CopyFeatures_management(ParOrionLayer, "memory/tempParReg")
ParOrion = arcpy.MakeFeatureLayer_management(ParOTempcopy, "memory/tempOrion")
m.addLayer(ParOrion, "TOP")

  File "<string>", line 85, in execute
  File "C:\Program Files\ArcGIS\Pro\Resources\ArcPy\arcpy\utils.py", line 191, in fn_
    return fn(*args, **kw)
  File "C:\Program Files\ArcGIS\Pro\Resources\ArcPy\arcpy\_mp.py", line 1843, in addLayer
    return convertArcObjectToPythonObject(self._arc_object.addLayer(*gp_fixargs((add_layer_or_layerfile, add_position), True)))
ValueError: memory/tempOrion

[Anonymous User]

Still seems to be a problem in ArcGIS Pro 3.0.2. 

[Anonymous User · Accepted solution]

I think I found the solution, at least for 3.0.2.

You have to make a feature layer, and then use the .getOutput() method on the results object to get the actual layer object. That can be added to a map. You still need to run the script from a toolbox inside of the map, since it's in memory, a standalone python script will add the layer to the map, but the connection to the data source will be broken.

If you look at the datatypes in the second screenshot you can see why it works.

 

[MattHowe]

Interesting, thanks @Anonymous User. I'll give that a shot.

[MattHowe]

@Anonymous User I can confirm this works. Thanks a lot and happy holidays when you get there!