Select Unique Combination of Values from Multiple Fields (python)

JakeNeedle

Hi All,

I'm new to python scripting and I was wondering if there is a way to select features with a unique combination of values from multiple fields. I would like to take each selection set of features and complete additional geoprocessing tasks on them and move on to the next selection of features with the same field values and repeat. 

The closest I have got so far is to produce a list of values that are unique in the feature class. I feel like this is not heading in the direction I would like it to. I am open to running the python in or outside of ArcGIS Pro.

import arcpy
import numpy

fc = "C:\Temp\ProjectModel.gdb\TempAvgs_ExportFeatures1"

arr = arcpy.da.FeatureClassToNumPyArray(fc, ['GeologicUnit', 'Analyte'])

uniqueRows = numpy.unique(arr)
print uniqueRows

JohannesLindner

The arcpy way of doing this:

import arcpy

fc = "C:\Temp\ProjectModel.gdb\TempAvgs_ExportFeatures1"
fields = ['GeologicUnit', 'Analyte']

unique_combinations = {
    row
    for row in arcpy.da.SearchCursor(fc, fields)
    }

for unit, analyte in unique_combinations:
    print(unit, analyte)
    # create a layer with all rows of that values combination
    sql = f"GeologicUnit = {unit} AND Analyte = {analyte}"  # add single quotes around {unit} and {analyte} if those fields are strings
    layer = arcpy.management.MakeFeatureLayer(fc, f"{unit}_{analyte}", sql)
    # do your geoprocessing on this layer
    arcpy.analysis.Intersect([layer, some_other_layer], f"Intersect_{unit}_{analyte}")