topic Re: Python Toolbox to create buffer layer in Python Questions

Python Toolbox to create buffer layer

BrandonPrice1 — Mon, 25 Aug 2025 17:12:15 GMT

Hello,

Can somebody advise me on how to code this properly? The below script was attempted using google AI snippets to create an in memory buffer layer of 500 feet based on the feature currently selected in the map. It throws an error when trying to run it. Also, if there is any advice on creating an editable layer from all features that intersect the buffer. Eventually, I plan to publish everything as a GP service.

import arcpy import arcpy.mp class Toolbox: def __init__(self): self.label = "Custom Buffer Tools" self.alias = "CustomBuffer" self.tools = [BufferSelectedFeatures] # Add your tool class here class BufferSelectedFeatures(object): def __init__(self): self.label = "Buffer Selected Features" self.description = "Creates a 500-foot buffer around selected features." self.canRunInBackground = False def getParameterInfo(self): param0 = arcpy.Parameter( displayName="Input Feature Layer", name="in_features", datatype="GPFeatureLayer", parameterType="Required", direction="Input") param1 = arcpy.Parameter( displayName="Output Buffer Layer Name", name="out_buffer_name", datatype="GPString", parameterType="Required", direction="Input") param1.value = "Selected_Feature_Buffer" # Default name return [param0, param1] def execute(self, parameters, messages): in_features = parameters[0].valueAsText out_buffer_name = parameters[1].valueAsText # Set the scratch workspace for temporary data arcpy.env.scratchWorkspace = "in_memory" # Create the full path for the output buffer feature class out_buffer_fc = arcpy.ValidateTableName(out_buffer_name, arcpy.env.scratchWorkspace) # Buffer the selected features arcpy.Buffer_analysis(in_features, out_buffer_fc, "500 Feet") messages.addMessage(f"Buffer created: {out_buffer_fc}") # Add the buffer layer to the map (for ArcGIS Pro) aprx = arcpy.mp.ArcGISProject("CURRENT") active_map = aprx.activeMap # Make a feature layer from the buffered output arcpy.management.MakeFeatureLayer(out_buffer_fc, out_buffer_name) new_layer = arcpy.mp.Layer(out_buffer_name) # Create a Layer object from the temporary layer # Add the layer to the active map active_map.addLayer(new_layer) messages.addMessage(f"Buffer layer '{out_buffer_name}' added to the map.") return

-Brandon

Re: Python Toolbox to create buffer layer

DanPatterson — Mon, 25 Aug 2025 17:20:39 GMT

and what would the error be?

Re: Python Toolbox to create buffer layer

TylerT — Mon, 25 Aug 2025 18:37:48 GMT

Hi @BrandonPrice1,

in-memory is legacy workspace. You might try memory depending on your ArcGIS version.

See memory docs here: https://pro.arcgis.com/en/pro-app/latest/help/analysis/geoprocessing/basics/the-in-memory-workspace.htm

Tyler

Re: Python Toolbox to create buffer layer

BrandonPrice1 — Mon, 25 Aug 2025 22:15:55 GMT

My apologies. Below is the error message. I tried changing in_memory to memory and got this same error.

Re: Python Toolbox to create buffer layer

HaydenWelch — Tue, 26 Aug 2025 12:25:31 GMT

mp.Layer is a class that you can't initialize. It's a representation of a program object. You can use it to type hint a return value, but if you want to create a layer, you need to use MakeFeatureLayer and assign the result to a variable.

import arcpy class Toolbox: def __init__(self): self.label = "Custom Buffer Tools" self.alias = "CustomBuffer" self.tools = [BufferSelectedFeatures] class BufferSelectedFeatures(object): def __init__(self): self.label = "Buffer Selected Features" self.description = "Creates a 500-foot buffer around selected features." self.canRunInBackground = False def getParameterInfo(self): in_features = arcpy.Parameter( name="in_features", displayName="Input Feature Layer", datatype="GPFeatureLayer", parameterType="Required", direction="Input") out_buffer_name = arcpy.Parameter( name="out_buffer_name", displayName="Output Buffer Layer Name", datatype="GPString", parameterType="Required", direction="Input") out_buffer_name.value = "Selected_Feature_Buffer" # Default name return [in_features, out_buffer_name] def execute(self, parameters: list[arcpy.Parameter], messages): params = {p.name: p for p in parameters} in_features = params['in_features'].value out_buffer_name = params['out_buffer_name'].value aprx = arcpy.mp.ArcGISProject("CURRENT") with arcpy.EnvManager(workspace='memory'): # Create the full path for the output buffer feature class out_buffer_fc = arcpy.ValidateTableName(out_buffer_name) # Buffer the selected features arcpy.analysis.Buffer(in_features, out_buffer_fc, "500 Feet") # Make a feature layer from the buffered output new_layer = arcpy.management.MakeFeatureLayer(out_buffer_fc, out_buffer_name)[0] arcpy.AddMessage(f"Buffer created: {out_buffer_fc}") # Add the layer to the active map aprx.activeMap.addLayer(new_layer) arcpy.AddMessage(f"Buffer layer '{out_buffer_name}' added to the map.")

Just a sidenote: with the workspace set to memory, the buffer layer will exist only in memory. You can accept a full derived layer path as a Parameter input if that's what you really want to do.

Re: Python Toolbox to create buffer layer

BrandonPrice1 — Wed, 27 Aug 2025 01:32:55 GMT

Thanks. I appreciate it.

Re: Python Toolbox to create buffer layer

BrandonPrice1 — Wed, 27 Aug 2025 01:31:01 GMT

Thanks again, this buffer tool intended to be used as a geoprocessing service. So, the newly generated buffer layer would be added to a webmap rather than a ArcGIS Pro Project. I will try using your sample and tweak it for online use.