topic Re: UpdateCursor Script Tool in Geoprocessing Questions

UpdateCursor Script Tool

Corey_C_Denninger — Wed, 12 May 2010 14:47:40 GMT

I am attempting to write a simple script tool that looks at one field, and if it meets a specified value(s) then populate another field with a String. I plan to make the script a bit longer and more complex, as of now, the simple version (below) does not work. Any help is appreciated. Thank you.

BTW - I beleive my indentations are correct, but the script is not posting/displaying below the way I indented.

import sys, string, os, arcgisscripting
gp = arcgisscripting.create(9.3)
gp.OverWriteOutput = 1

#gp.workspace = "L:\\GIS\Layers\\Geodatabases\\Land_Use_Cover\\Districtwide_LULC_Analysis.mdb"

FC = sys.argv[1]
LEV2 = sys.argv[2]
UpdateField = sys.argv[3]

cur = gp.UpdateCursor(FC)
row = cur.Next()

while row:
            if row.GetValue(LEV2) == 11:
            row.SetValue(UpdateField,"Urban & Built-Up")
            cur.UpdateRow(row)
      row = cur.Next()

del cur
del row

Re: UpdateCursor Script Tool

JohnHauck — Fri, 10 Dec 2021 20:59:13 GMT

I don't see anything wrong with the code. Try running the following from a Python IDE to see if you can notice anything else.

import sys, string, os, arcgisscripting
gp = arcgisscripting.create(9.3)
gp.OverWriteOutput = 1

FC = r"C:\Program Files\ArcGIS\DeveloperKit\SamplesNET\data\Atlanta.gdb\streets"
LEV2 = "JoinId"
UpdateField = "CITYL"

try:
    cur = gp.UpdateCursor(FC)
    row = cur.Next()
    while row:
        if row.GetValue(LEV2) == 1:
            row.SetValue(UpdateField, "Urban & Built-Up")
            cur.UpdateRow(row)
        row = cur.Next()
except:
    print gp.getmessages(0)
    gp.addmessage(gp.getmessages(0))

del cur, row

Re: UpdateCursor Script Tool

Corey_C_Denninger — Wed, 12 May 2010 16:56:08 GMT

Thanks for the assistance. I did as you suggested. I closed ArcCatalog/Map, ran from IDLE, completes successfully with no Errors messages. Open feature class, no Updates made to the field even though the parameters are met. The LEV2 field is a Short Interger field and the CATEGORY field is a String/Text field. Here is the script you posted, modified for my file locations/names.
***********************
import sys, string, os, arcgisscripting
gp = arcgisscripting.create(9.3)
gp.OverWriteOutput = 1

FC = "L:\\GIS\Layers\\Geodatabases\\Land_Use_Cover\\Districtwide_LULC_Analysis.mdb\\District_LULC_Counties_Cities_99_Id"
LEV2 = "LEV2"
UpdateField = "CATEGORY"

try:
    cur = gp.UpdateCursor(FC)
    row = cur.Next()
    while row:
        if row.GetValue(LEV2) == 11:
            row.SetValue(UpdateField, "Urban & Built-Up")
            cur.UpdateRow(row)
        row = cur.Next()
except:
    print gp.getmessages(0)
    gp.addmessage(gp.getmessages(0))

del cur, row

Re: UpdateCursor Script Tool

RDHarles — Fri, 10 Dec 2021 20:59:16 GMT

Just for fun, I ran the code (only changing the 3 variables to fit my test file) and it worked perfectly.
No idea why it wouldn't work for you???
p.s. I assume your path doesn't really have those spaces in it.
p.s.s. When you copy and past code for a post, highlight just the code and hit the "#" button. That will keep the formatting.

import sys, string, os, arcgisscripting
gp = arcgisscripting.create(9.3)
gp.OverWriteOutput = 1

FC = "C:/junk/db1.mdb/table1"
# number
LEV2 = "nm_area"
# text
UpdateField = "TEST"

try:
    cur = gp.UpdateCursor(FC)
    row = cur.Next()
    while row:
        if row.GetValue(LEV2) == 1:
            row.SetValue(UpdateField, "Urban & Built-Up")
            cur.UpdateRow(row)
        row = cur.Next()
except:
    print gp.getmessages(0)
    gp.addmessage(gp.getmessages(0))

del cur, row

Re: UpdateCursor Script Tool

Corey_C_Denninger — Fri, 10 Dec 2021 20:59:19 GMT

I got it to work. It wasn't the code (as you stated), but my personal geodatabase had reached its size limits and the tool wouldn't function because, I assume, by adding those text strings to my feature classes it pushed the whole gdb over the 2GB limit. I placed into a file gdb and we're good to go. I modified the script to function as a script tool. I am sure there is a more efficient way to write this script (lists, tuples, etc). If anyone has suggestions, great...if not, it works fine. My scripting is getting better, but is very basic at this point.

Also, does anyone know how I credit someone with successfully assisting me (like in the old Forum) so they get their points, etc?

import sys, string, os, arcgisscripting
gp = arcgisscripting.create(9.3)
gp.OverWriteOutput = 1

FC = gp.GetParameterAsText(0)
LEV2 = sys.argv[2]
LEV1 = sys.argv[3]
UpdateField = sys.argv[4]

cur = gp.UpdateCursor(FC)
row = cur.Next()

#A = [11,12,13,14,17,18,19]
#B = [15,16]
#C = [21,22,23,24,25,26,27,28,29]

while row:
      if row.GetValue(LEV2) == 11:
            row.SetValue(UpdateField,"Urban & Built-Up")
      elif row.GetValue(LEV2) == 12:
            row.SetValue(UpdateField,"Urban & Built-Up")
      elif row.GetValue(LEV2) == 13:
            row.SetValue(UpdateField,"Urban & Built-Up")
      elif row.GetValue(LEV2) == 14:
            row.SetValue(UpdateField,"Urban & Built-Up")
      elif row.GetValue(LEV2) == 17:
            row.SetValue(UpdateField,"Urban & Built-Up")
      elif row.GetValue(LEV2) == 18:
            row.SetValue(UpdateField,"Urban & Built-Up")
      elif row.GetValue(LEV2) == 19:
            row.SetValue(UpdateField,"Urban & Built-Up")
      elif row.GetValue(LEV2) == 15:
            row.SetValue(UpdateField,"Industrial & Mining")
      elif row.GetValue(LEV2) == 16:
            row.SetValue(UpdateField,"Industrial & Mining")
      elif row.GetValue(LEV1) == 2:
            row.SetValue(UpdateField,"Agriculture")
      elif row.GetValue(LEV1) == 3:
            row.SetValue(UpdateField,"Rangeland")
      elif row.GetValue(LEV1) == 4:
            row.SetValue(UpdateField,"Upland Forest")
      elif row.GetValue(LEV1) == 5:
            row.SetValue(UpdateField,"Water")
      elif row.GetValue(LEV1) == 6:
            row.SetValue(UpdateField,"Wetlands")
      elif row.GetValue(LEV1) == 7:
            row.SetValue(UpdateField,"Barren Land")
      elif row.GetValue(LEV1) == 8:
            row.SetValue(UpdateField,"Trans, Comm, & Util") 
      cur.UpdateRow(row)
      row = cur.Next()
del cur

Re: UpdateCursor Script Tool

RDHarles — Fri, 10 Dec 2021 20:59:22 GMT

To avoid duplicating code, you could do something like this using your lists and the 'in' operator:

A = [11,12,13,14,17,18,19]
B = [15,16]

while row:
      if row.GetValue(LEV2) in A:
            row.SetValue(UpdateField,"Urban & Built-Up")
      if row.GetValue(LEV2) in B:
            row.SetValue(UpdateField,"Industrial & Mining")

Re: UpdateCursor Script Tool

Corey_C_Denninger — Fri, 10 Dec 2021 20:59:24 GMT

That did it. Thanks for all the help R.D. I'm surprised though, that not 'elif' statements are needed and the 'if' alone works just fine. How do I credit you with assisting me on this post and mark 'completed', etc....like in the old Forum? Are there no longer points awarded?

Here is the script as I have it now. Saved a few rows and characters from the final script...thanks again:

import sys, string, os, arcgisscripting
gp = arcgisscripting.create(9.3)
gp.OverWriteOutput = 1

FC = gp.GetParameterAsText(0)
LEV2 = sys.argv[2]
LEV1 = sys.argv[3]
UpdateField = sys.argv[4]

cur = gp.UpdateCursor(FC)
row = cur.Next()

A = [11,12,13,14,17,18,19]
B = [15,16]
C = [2]
D = [3]
E = [4]
F = [5]
G = [6]
H = [7]
I = [8]


while row:
      if row.GetValue(LEV2) in A:
            row.SetValue(UpdateField,"Urban & Built-Up")
      if row.GetValue(LEV2) in B:
            row.SetValue(UpdateField,"Industrial & Mining")
      if row.GetValue(LEV1) in C:
            row.SetValue(UpdateField,"Agriculture")
      if row.GetValue(LEV1) in D:
            row.SetValue(UpdateField,"Rangeland")
      if row.GetValue(LEV1) in E:
            row.SetValue(UpdateField,"Upland Forest")
      if row.GetValue(LEV1) in F:
            row.SetValue(UpdateField,"Water")
      if row.GetValue(LEV1) in G:
            row.SetValue(UpdateField,"Wetlands")
      if row.GetValue(LEV1) in H:
            row.SetValue(UpdateField,"Barren Land")
      if row.GetValue(LEV1) in I:
            row.SetValue(UpdateField,"Trans, Comm, & Util")
      cur.UpdateRow(row)
      row = cur.Next()
del cur

Re: UpdateCursor Script Tool

RickyLindley — Thu, 03 Jun 2010 14:14:22 GMT

Along the same type of updatecursor script, I am needing help on a script that will look at the first record in a table and update a field in a featureclass. This would be a one to many field update.
The table is called ProjectList, its has fields Category, Subno and ProjectName. Each record in the table is unique.
The featureclass is called Water and it has the same 3 fields as the table, but multiple records with the same Category and Subno.....the ProjectName is blank or incorrect.
I am trying to write a script that will go to the first record in the ProjectList table and update each ProjectName in the Water featureclass with ProjectName from the ProjectList table. Then continue to the next record in the table and repeat until it reaches the end of the table. Thanks.

Re: UpdateCursor Script Tool

RDHarles — Thu, 03 Jun 2010 14:43:57 GMT

Corey,

Glad I could help.

I prefer using only "if" statements. That way each statement is evaluated individually instead of the whole thing being tied together in an if/elif/else.

Not sure if they are bringing back the credit/completed/points system. I thought I read somewhere that they were but it appears it is not working now.

Re: UpdateCursor Script Tool

RDHarles — Fri, 10 Dec 2021 20:59:27 GMT

rickyl15,
Here's an example of reading from a table (dbf file) and writing to fc (shapefile).
The SearchCursor reads the dbf, the UpdateCursor writes to the fc.
This should give you a pretty good start.

## Read the dbf and populate the shp.

import arcgisscripting, sys, os
gp = arcgisscripting.create()

gp.workspace = os.getcwd()

dbf = "Apr.dbf"
shp = "Apr2009.shp"

# dbf loop
rows = gp.SearchCursor(dbf)
row = rows.Next()
while row:
    
    # Get the value from the field(dbf)
    value = row.GetValue("ID_NUM")
    
    print "Processing ID_NUM = "+str(value)
        
    # shp loop    
    rows2 = gp.UpdateCursor(shp)
    row2 = rows2.Next()
    while row2:
        # Get the value from the field (shp)
        value2 = row2.GetValue("ID_NUM")

        # Populate field in shp based on a match        
        if value2 < 1740:            
            row2.city_legal = "Lower"      
        if value2 > 1739:            
            row2.city_legal = "Higher"

        # Execute the new value to the shp
        rows2.UpdateRow(row2)            
        # shp next
        row2 = rows2.Next()         
    
    # dbf next
    row = rows.Next()

del rows2
del rows

print "\nDone.\n"

Re: UpdateCursor Script Tool

RickyLindley — Thu, 03 Jun 2010 19:04:56 GMT

rdharles, thanks for the quick post. I am a novice at this and it's been a few years since I have taken the intro class so it might take me a while to incorporate my information into the code to test. This should give me a really good start.

Thanks Again

Below is my last attempt before I gave up last time.

import win32com.client

gp = win32com.client.Dispatch("esriGeoprocessing.GpDispatch.1")

gp.Workspace = "C:\\GISProjects\\ProjectListUpdate.mdb"

inputFC = "Lines"
TAB = "PROJECTLIST"

cur1 = gp.SearchCursor(TAB)

row1 = cur1.Next()

c = row1.GetValue("CATEGORY")
s = row1.GetValue("SUBNO")
p = row1.GetValue("PROJECT")

print c
print s
print p

cur2 = gp.SearchCursor(inputFC)
row2 = cur2.Next()

t = row2.GetValue("Category")
l = row2.GetValue("LISTNUM")
n = row2.GetValue("SUBDIV")
field = "SUBDIV"

print t
print l
print n

print c
print s
print p

if "Category" == c and "LISTNUM" == s:
    cur = gp.UpdateCursor(inputFC)
    row2 = cur2.Next()
while row2:
    row2.SetValue(field, row2.SUBDIV, row1.PROJECT)
    cur2.UpdateRow(row2)
    row2 = cur2.Next()
else:
    row1 = cur1.Next()




del cur

Re: UpdateCursor Script Tool

RickyLindley — Mon, 07 Jun 2010 18:42:01 GMT

rdharles, still not working...any ideas? Thanks.

import win32com.client

gp = win32com.client.Dispatch("esriGeoprocessing.GpDispatch.1")

gp.Workspace = "C:\\GISProjects\\ProjectListUpdate.mdb"

FC = "Lines"
TAB = "PROJECTLIST"

#Table Loop
cur1 = gp.SearchCursor(TAB)
row1 = cur1.Next()
while row1:
    #Get the values from the fields(tab)
    c = row1.GetValue("CATEGORY")
    s = row1.GetValue("SUBNO")
    p = row1.GetValue("PROJECT")

    print "Table Category ="+str(c)
    print "Table Subno ="+str(s)
    print "Table Project Name ="+str(p)

    #fc loop
    cur2 = gp.SearchCursor(FC)
    row2 = cur2.Next()
    while row2:
        #Get the values from the fields(fc)
        t = row2.GetValue("Category")
        l = row2.GetValue("LISTNUM")
        n = row2.GetValue("SUBDIV")

        #Populate field in the fc based on a match
        if t == c and l == s:
            row2.SUBDIV = p

        #Execute the new value to the fc
        cur2.UpdateRow(row2)
        #fc next
        row2 = cur2.Next()

    #table next
    row1 = cur1.Next()

del cur2
del cur1

print "\nDone. \n"

Re: UpdateCursor Script Tool

RDHarles — Mon, 07 Jun 2010 18:48:00 GMT

What sort of error are you getting?

Re: UpdateCursor Script Tool

RickyLindley — Mon, 07 Jun 2010 19:17:45 GMT

What sort of error are you getting?

>>> Table Category =D
Table Subno =5865
Table Project Name =McDermott Road, East from Coit Road.
Traceback (most recent call last):
File "C:\Python25\Lib\site-packages\pythonwin\pywin\framework\scriptutils.py", line 325, in RunScript
exec codeObject in __main__.__dict__
File "C:\Student\MyFolder\test1.py", line 37, in <module>
cur2.UpdateRow(row2)
File "<COMObject <unknown>>", line 2, in UpdateRow
com_error: (-2147352567, 'Exception occurred.', (0, u'DAO.TableDefs', u'Item not found in this collection.', u'jeterr40.chm', 5003265, -2147467259), None)
>>>

Re: UpdateCursor Script Tool

RDHarles — Mon, 07 Jun 2010 19:50:35 GMT

I think I see it, the cursor on your FC needs to be a UpdateCursor (not a SearchCursor).

Re: UpdateCursor Script Tool

RickyLindley — Mon, 07 Jun 2010 20:31:59 GMT

I think I see it, the cursor on your FC needs to be a UpdateCursor (not a SearchCursor).

That seems to be it...thanks . I will run it on some test data tomorrow.

Thanks Again.

Re: UpdateCursor Script Tool

RickyLindley — Tue, 08 Jun 2010 14:16:13 GMT

I think I see it, the cursor on your FC needs to be a UpdateCursor (not a SearchCursor).

Tested this morning the code runs without any errors....however it doesn't replace the SUBDIV in the FC with the data from the table.

#Populate field in the fc based on a match
        if t == c and l == s:
            print "Match"
            row2.SUBDIV = p

        #Execute the new value to the fc
        cur2.UpdateRow(row2)
        #fc next
        row2 = cur2.Next()

Re: UpdateCursor Script Tool

RickyLindley — Thu, 10 Jun 2010 15:43:27 GMT

Tested this morning the code runs without any errors....however it doesn't replace the SUBDIV in the FC with the data from the table.

#Populate field in the fc based on a match
        if t == c and l == s:
            print "Match"
            row2.SUBDIV = p

        #Execute the new value to the fc
        cur2.UpdateRow(row2)
        #fc next
        row2 = cur2.Next()

Any ideas on why the new SUBDIV data does not show in the FC?

Re: UpdateCursor Script Tool

RDHarles — Fri, 11 Jun 2010 11:16:19 GMT

Any ideas on why the new SUBDIV data does not show in the FC?

Is it printing the word "Match" and not writing anything or is it not getting into the if statement at all?

Re: UpdateCursor Script Tool

RickyLindley — Fri, 11 Jun 2010 18:03:25 GMT

Is it printing the word "Match" and not writing anything or is it not getting into the if statement at all?

It looks like it is this part of the code that is not working for some reason. It's not updating the FC field called SUBDIV with the information that is in variable p.
When I open the FC it still has the old info in it. Thanks.

#Execute the new value to the fc
cur2.UpdateRow(row2)
#fc next
row2 = cur2.Next()