I want to make my field buff_dist longer than by 400ft. I want to write a code that will go through the table and change the field value by adding 400ft to it's value.

How would I write that?

I tried to use UpdateCursor, but I don't think I was understanding it. I also want to be able to select certain objects to change the buff_dist field of, but knowing how to change the field value is one step closer for me!

closed as off-topic by PolyGeo Mar 3 at 12:03

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Using Field Calculator (simple):


Or in ArcMap by opening the attribute table, right click on the Buffer_Field and then in the dialog enter Buffer_Field + 400.

Using update cursor (somewhat advanced):

import arcpy

InTable = "c:\\path\\to\\table" # or feature class

with arcpy.da.UpdateCursor(InTable,["Buffer_Field"]) as UpCur:
    for row in UpCur:
        row[0] = row[0] + 400

Note: this is bare bones code with no error checking for Null values or string field types, that gets a little more advanced.

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