topic Re: Graduated Colors Renderer On Existing Layer Not Successful in Python Questions

Graduated Colors Renderer On Existing Layer Not Successful

JaredPilbeam2 — Thu, 02 Sep 2021 16:59:15 GMT

Using the below script, I'm not able to change a layers symbology if it is already set. For example, I have three layers with 4 break values and labels each. The intention of the script is to change a break value and label. If I run the script on the layers as they exist currently, the script runs successfully, but the changes aren't made and I get an error of sorts in the Symbology pane.

Three graduated colors layers before running script.

I change a break value from 55.3 to 56.3, and it's corresponding label. Then I run the script.

import arcpy, os, sys # Reference a project, map, and layer using arcpy.mp p = arcpy.mp.ArcGISProject('current') m = p.listMaps()[0] lyr = m.listLayers() for l in lyr[1:4]: sym = l.symbology if hasattr(sym, 'renderer'): if sym.renderer.type == 'GraduatedColorsRenderer': sym.renderer.classificationField = 'VaccPercentageTotPop' print(f'changing layer symbology for {l}') #enter class break values classBreakValues = [40, 45, 56.3, 100] classBreakLabels = ["0% - 40%", "40.01% - 45%", "45.01% - 56.3%", "55.31% - 100%"] # Run the renderer.breakCount function to use the classBreakValues array parameters as the values, and create a counter. sym.renderer.breakCount = len(classBreakValues) count = 0 #Create a loop to set the renderer for brk in sym.renderer.classBreaks: brk.upperBound = classBreakValues[count] brk.label = classBreakLabels[count] count +=1 l.symbology = sym p.save() ###prints: ### changing layer symbology for Elementary Districts ### changing layer symbology for Secondary Districts ### changing layer symbology for Unified Districts

The following is what happens. I get a warning in the Symbology pane (which doesn't tell me much).

And my layers no longer have values.

Re: Graduated Colors Renderer On Existing Layer Not Successful

DanPatterson — Thu, 02 Sep 2021 20:00:20 GMT

I don't suppose "CURRENT" would be the cause given that this is python and assuming esri would be following pythonic adherence to case sensitivity etc ....

Re: Graduated Colors Renderer On Existing Layer Not Successful

JaredPilbeam2 — Thu, 02 Sep 2021 20:18:47 GMT

"CURRENT" and "current" seem to be interchangeable I've found.

However, if I reset the layers' symbology, and then run the script it works fine. But, I won't be resetting the symbology every time just so I can run the script, of course. By "reset" I mean physically changing the symbology: Graduated Colors --> Unique Values --> back to Graduated Colors.

For some reason, it doesn't like that the symbology is already set as Graduated Colors.

Re: Graduated Colors Renderer On Existing Layer Not Successful

JaredPilbeam2 — Thu, 02 Sep 2021 20:37:00 GMT

I've also tried the script as a standalone. No cigar.

Re: Graduated Colors Renderer On Existing Layer Not Successful

DanPatterson — Thu, 02 Sep 2021 23:08:05 GMT

but sadly you didn't get an error message for little "current".

Now that you mention it, I have found your "Graduated Colors --> Unique Values --> back to Graduated Colors" my experience when working manually with classifications... It is almost instinctive now that you mention it.