Problem using Arcpy Update Cursor

Question

Hi all,
I'm trying to loop through all the rows of a shapefile field and update the row values, and can't get the Arcpy Update Cursor to work properly. My script crashes when I try to pass the new value that I want to update the row object with. I've tried passing the value as an integer and a string (the field I'm trying to update is an integer type), and I've tried using the row.setValue method as well. Below is my code for creating and using the cursor (code would be properly indented in PyScriptor). If anyone can tell me what I'm doing wrong I would really appreciate it.

rows = arcpy.UpdateCursor(outshp,"","",fname,"")
for row in rows:

isyear = 1
         row.fname = isyear
         rows.updateRow(row)
 
del row
 del rows

thanks in advance!

Billy

BillyArmstrong · Answer

Thanks for the replies. I ended up using the Field Calculator and it worked great.

Billy

RobertJones6 · Answer

Another way you could try it would be like the following, since your code succeeds with manual field naming versus derived:rows = arcpy.UpdateCursor(outshp,"","",      ---> "%s" %(fname,) <-----    ,"")

jskinner · Answer

I don't believe you will be able to pass a variable for a Update/Search/Insert Cursor.  When you specify 'row.fname', the cursor looks for a field called 'fname', even if 'fname' was defined as a variable before hand.  The cursor cannot distinguish this.  I would recommend using the Field Calculator.  You can pass a variable with this function.  Ex:outshp = "Test.shp"

fname = "id"
isyear = 1

arcpy.CalculateField_management(outshp, fname, isyear)