Dissolving together Territorial Authority Local Boards TALB to Territorial Authority areas

example.py

import arcpy

# Input and output feature classes
in_fc = r"C:\Users\BhodanSzymanilk\wd\SimplifiedVictimisationByStationAtTAGrain\SimplifiedVictimisationByStationAtTAGrain.gdb\census2023TALBpopulations"
output_fc = r"C:\Users\BhodanSzymanilk\wd\SimplifiedVictimisationByStationAtTAGrain\SimplifiedVictimisationByStationAtTAGrain.gdb\Census2023TApopulations"

# create a new field that uniquely identifies each TA - we grab the first 3 numbers from TALB2023_V - check if it exists firts
# all the Auckland local boards are identified with an initial '076' followed by numbers specific to the local board
TAID = "TAID"
for fieldname in [field.name for field in arcpy.ListFields(in_fc)]:
    print(fieldname)
    
if TAID in [field.name for field in arcpy.ListFields(in_fc)]:
    print(f"Field '{TAID}' already exists - deleting...")
    arcpy.management.DeleteField(in_fc, TAID)
else:
    print(f"Field '{TAID}' does not exist.")

arcpy.AddField_management(
    in_table=in_fc,
    field_name=TAID, 
    field_type="TEXT",
    field_length=3,          # field_length (optional, for text fields)
    field_alias=TAID,    # field_alias (optional)
    field_is_nullable="NULLABLE",  # Make the field nullable
    field_is_required="NON_REQUIRED"  # Field is not required - if set as required then you won't be able to delete - by design https://support.esri.com/en-us/knowledge-base/error-error-001334-cannot-delete-required-field-field-000014937
    # field_domain
)

# now populate

old_field_name = "TALB2023_V"
arcpy.CalculateField_management(in_fc, TAID, f"!{old_field_name}![:3]", "PYTHON3")

# Field to dissolve on (e.g., "LandUseType")
dissolve_field = TAID

# Perform the dissolve
arcpy.management.Dissolve(
    in_features=in_fc, 
    out_feature_class=output_fc, 
    dissolve_field=dissolve_field,
    statistics_fields=[ 
        ["TALB2023_V","FIRST"],
        ["TALB2023_1","FIRST"],
        ["TALB2023_2","FIRST"],
        ["VAR_1_2","SUM"],
        ["VAR_1_3","SUM"],
        ["VAR_1_4","SUM"],
        ["VAR_1_5","SUM"],
        ["VAR_1_6","SUM"],
        ["VAR_1_7","SUM"],
        ["VAR_1_8","SUM"],
        ["VAR_1_9","SUM"],
        ["VAR_1_10","SUM"],
        ["VAR_1_11","SUM"],
        ["VAR_1_12","SUM"],
        ["VAR_1_13","SUM"],
        ["VAR_1_14","SUM"],
        ["VAR_1_15","SUM"],
        ["VAR_1_16","SUM"],
        ["VAR_1_17","SUM"],
        ["VAR_1_18","SUM"],
        ["VAR_1_19","SUM"],
        ["VAR_1_20","SUM"],
        ["VAR_1_21","SUM"],
        ["VAR_1_22","SUM"],
        ["VAR_1_23","SUM"],
        ["VAR_1_24","SUM"],
        ["VAR_1_25","SUM"]
    ]
)