Multiplying values within ArcPy update cursor?

Question

This code is meant to apply an update cursor to a field called "New_Sq_Mile" when I am populating the field with the area of the polygons. Unfortunately the units are in meters and I need to do a calculation to change those values to miles before they are updated into the table. Here is what I have so far.

cursor = arcpy.UpdateCursor(FinalErase, ["SHAPE@AREA", "New_Sq_Mile"])
for row in cursor:
 row[1] = row[0]
 update.row
del row
del cursor

Is there a way I can do a calculation in the for loop such as

row[1] = row[0]/1606.344

• Bera: Btw: 1 square meter is not 1/1606,344 square mile

Answer 1

You should use the newer Data Access module Cursors, for example da.UpdateCursor. They are alot faster. In your case like this:

import arcpy
with arcpy.da.UpdateCursor(FinalErase,["SHAPE@AREA","New_Sq_Mile"]) as cursor:
 for row in cursor:
 row[1]=row[0]/1606.344
 cursor.updateRow(row)

• Noah P: It worked! Thank you. I am a student and did not realize there was a difference between cursors and data access module cursors.