Set a graduated colors renderer with manual intervals in ArcGIS Pro using Python

Summary

Graduated colors symbology is used to show a quantitative difference between mapped features by varying the color of symbols. Data is classified into ranges that are each assigned a different color from a color scheme to represent the range. Refer to ArcGIS Pro: Graduated colors for more information.

It is possible to set a graduated colors renderer using the ArcPy module through the GraduatedColorsRenderer class.

Procedure

The following steps describe how to set a graduated colors renderer using the ArcPy module:

1. Import the necessary modules.

import arcpy

2. Create the parameter to specify the current project and maps.

p = arcpy.mp.ArcGISProject("CURRENT")
m = p.listMaps("Map")[0]
lyr = m.listLayers()[0]
sym = lyr.symbology

3. Run the function to use the GraduatedColorsRenderer class and the color specification.

sym.updateRenderer("GraduatedColorsRenderer")
sym.renderer.colorRamp=p.listColorRamps("Cyan to Purple")[0]

4. Create the parameters to set the value intervals.

classBreakValues = [25000,150000,1000000,3000000,10000000]
classBreakLabels = ["div 1", "div 2", "div 3", "div 4", "div 5"]

5. 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

6. Create a loop to set the renderer.

for brk in sym.renderer.classBreaks:
    brk.upperBound = classBreakValues[count]
    brk.label = classBreakLabels[count]
    count += 1
lyr.symbology = sym

The following shows the full script:

import arcpy

p = arcpy.mp.ArcGISProject("CURRENT")
m = p.listMaps("Map")[0]
lyr = m.listLayers()[0]
sym = lyr.symbology

sym.updateRenderer("GraduatedColorsRenderer")
sym.renderer.colorRamp=p.listColorRamps("Cyan to Purple")[0]

classBreakValues = [25000,150000,1000000,3000000,10000000]
classBreakLabels = ["div 1", "div 2", "div 3", "div 4", "div 5"]

sym.renderer.breakCount = len(classBreakValues)
count = 0

for brk in sym.renderer.classBreaks:
    brk.upperBound = classBreakValues[count]
    brk.label = classBreakLabels[count]
    count += 1
lyr.symbology = sym