Add value to a field Python

Question

I have a feature Class with the columns KOMMUNE and GKR and some other columns.. Both columns are string. In the column KOMMUNE I have the value 0723 and 0724. In column GKR I have the value 0107 and 0108. My problem is: If column KOMMUNE has the value 0723 i will add 2000 to the value 0107 in the colum GKR so the value becomes 2107 and if the value in KOMMUNE is 0724 I will add 3000 to the value 0108 in the colum GKR so the value becomes 3108.

Have tried with arcpy.CalculateField_management but I can not select the values ​​with it.

import sys, string, os, arcpy

from arcpy import env

env.workspace = r"C:\Tom\ArcPyTest\Slå sammen kommuner"

#Kommune_1 = arcpy.GetParameterAsText(0)

#Kommune_2 = arcpy.GetParameterAsText(1)

#Nytt_Kommune_Nr = arcpy.GetParameterAsText(2)



Kommune_1 = 723

Kommune_2 = 720

Nytt_Kommune_Nr = "0722"

FcKommune = r"C:\Tom\ArcPyTest\Slå sammen kommuner\07_Vestfold inn.gdb\gkr2013_brutto07"

arcpy.env.overwriteOutput = True

arcpy.AddField_management(FcKommune, "KOM", "TEXT", '', '', 4)
arcpy.AddField_management(FcKommune, "GKR", "TEXT", '', '', 4)

arcpy.AddField_management(FcKommune, "KOMMUNE", "TEXT", '', '', 4)
arcpy.CalculateField_management(FcKommune, "KOMMUNE",  "!" + "KOMM" + "!", "PYTHON")



rows = arcpy.da.UpdateCursor(FcKommune, ["KOMMUNE", "GRUNNKRETS", "KOM", "GKR"])

for row in rows:
    if (row[0]) == str(Kommune_1):
        row[2] = str(Nytt_Kommune_Nr)
    if (row[0]) == str(Kommune_1):
        row[3] = (row[1] [4:8])
    if (row[0]) == str(Kommune_2):
        row[2] = str(Nytt_Kommune_Nr)
    if (row[0]) == str(Kommune_2):
        row[3] = (row[1] [4:8])

    if (row[0]) == str(Kommune_1):
        arcpy.CalculateField_management(FcKommune, "GKR", "[GKR] +2000" , "VB", "")
    if (row[0]) == str(Kommune_2):
        arcpy.CalculateField_management(FcKommune, "GKR", "[GKR] +3000" , "VB", "")

    rows.updateRow(row)

Answer 1

I have tested "[GKR]+2000" with the CalculateField tool in ArcToolbox. It works well, even if GKR is a text field. Maybe you could try without the space between [GKR] and +2000.

Answer 2

You use CalcuateField_management for an entire feature layer, not one row at a time... try replacing your "for row in rows:" section...

for row in rows:
    if (row[0]) == str(Kommune_1):
        row[2] = str(Nytt_Kommune_Nr)
        row[3] = (row[1] [4:8])
        row[3] = str(int(row[3]) + 2000)

    if (row[0]) == str(Kommune_2):
        row[2] = str(Nytt_Kommune_Nr)
        row[3] = (row[1] [4:8])
        row[3] = str(int(row[3]) + 3000)

    rows.updateRow(row)