Sum values depending on another field in ArcPy

Question

I have two feature classes that are both parcels. They have a field for residential type with the values being either "Residential" or "Non-Residential". They also have another field for the shape area. I am trying to write a script with arcpy that will go through the feature classes and create a row in a new table that has the name, residential type, and the total area. I am having trouble with getting the code to select and add to the table to residential types. I am also trying to do this using cursors.

This is what I have so far

import arcpy
from arcpy import env
import os
env.overwriteOutput = 1
env.workspace = "C://Users//dylan//Downloads//Data5//Montgomery.gdb"
tab = "SummaryTable"
fcs = arcpy.ListFeatureClasses("*", "Polygon")
arcpy.CreateTable_management(env.workspace, tab)
arcpy.AddField_management(tab, "name", "string")
arcpy.AddField_management(tab, "restype", "string")
arcpy.AddField_management(tab, "area", "float")
tabcur = arcpy.da.InsertCursor(env.workspace + os.sep + tab, ["name","restype","area"])

• PolyGeo: I would use the Summary Statistics tool to do this in one line of code.
• GBG: The path to your workspace is not formatted correctly. pro.arcgis.com/en/pro-app/latest/arcpy/get-started/…
• dwallis25: @GBG , That way isn't listed in the link you sent but the way I have it works correctly.

Answer 1

If you are insisting on using cursors, then one approach would be like this. Where there is a SearchCursor used to sum up the area field using a where clause to select just the residential type you require.

import arcpy
from arcpy import env
import os
def get_sum_field_value(in_table, field_name="OID@", where_clause=None):
 """Return the total value of a field in a table."""
 return sum(
 (r[0] for r in arcpy.da.SearchCursor(in_table, field_name, where_clause))
 )
env.overwriteOutput = True
env.workspace = "C:/Users/dylan/Downloads/Data5/Montgomery.gdb"
tab = "SummaryTable"
arcpy.CreateTable_management(env.workspace, tab)
arcpy.AddField_management(tab, "name", "string")
arcpy.AddField_management(tab, "restype", "string")
arcpy.AddField_management(tab, "area", "float")
tabcur = arcpy.da.InsertCursor(env.workspace + os.sep + tab, ["name","restype","area"])
fcs = arcpy.ListFeatureClasses("*", "Polygon")
for fc in fcs:
 res = get_sum_field_value(fc, field_name="area", where_clause ='restype= "Residential"')
 tabcur.insertRow((fc, "Residential", res))
 non_res = get_sum_field_value(fc, field_name="area", where_clause ='restype= "Non-Residential"')
 tabcur.insertRow((fc, "Non-Residential", non_res))
del tabcur