query issues with Update Cursor

Question

Hello All,

I am working on an update cursor on a contour line feature class. The goal is to update a field "INDEX_VALU" with the string "10 foot Index" where data in the "CONTOUR" field are divisible by 10. In tests I was success when setting a simple query as shown:query = ' "CONTOUR" = 5100'

The issues occurs when I try to modify this query to include all values divisible by 10. I believe the modulo operator is the way forward, but they query keeps getting rejected. Enclosed is my latest attempt at solving this. Any help will be appreciated.# Script Name: contourindexcalc.py # Author: Stephen Gushue # Purpose: Find and calculate values of the contours to illustrate 10 foot contours  # Import system modules import arcpy, sys, traceback from arcpy import env  # Set workspace arcpy.env.workspace = 'U:\GEO\projects\python'  # Local Variables featureclass = 'contours_test.shp' fieldlist = arcpy.ListFields (featureclass)  try:     # Sets row hold query     setfield = '"CONTOUR"%'     query = 'setfield == 0'          # Create a Search Cursor     srows = arcpy.SearchCursor (featureclass, query)      for srow in srows:          # assign a variable for the value of srow.CONTOUR         # assign a variable for the value of srow.INDEX_VALU         contour = srow.CONTOUR         index = srow.INDEX_VALU                    # Create Update Cursor         urows = arcpy.UpdateCursor(featureclass, query)          # Cycle through the rows         # to actually update the row in the cursor         # with the values obtained from the search cursor         for urow in urows:             urow.INDEX_VALU = "10 Foot Index"             urows.updateRow(urow)      print 'DONE'     del urow, urows, srow, srows  except:      tb = sys.exc_info()[2]     tbinfo = traceback.format_tb(tb)[0]     pymsg = "PYTHON ERRORS:
Traceback Info:
" + tbinfo + "
Error Info:
"     msgs = "ARCPY ERRORS:
" + arcpy.GetMessages(2) + "
"      arcpy.AddError(msgs)     arcpy.AddError(pymsg)      print msgs     print pymsg

MathewCoyle · Accepted Answer

I think you need to start at square one here. There is no reason to use a search cursor and an update cursor at the same time on the same feature class.

This should be all you need in your try statement.try:     # Create Update Cursor     urows = arcpy.UpdateCursor(featureclass)      # Cycle through the rows     # to actually update the row in the cursor     # with the values obtained from the search cursor     for urow in urows:         contour = urow.CONTOUR         if int(float(contour) / 10) == (float(contour) / 10):             urow.INDEX_VALU = "10 Foot Index"         urows.updateRow(urow)      print 'DONE'     del urow, urows