topic need help with UpdateCursor and .updateRow(row)!!! in Python Questions

need help with UpdateCursor and .updateRow(row)!!!

AndrewWickham — Tue, 21 May 2013 14:35:09 GMT

Hi all,

I am studying python scripting for geoprocessing and am having trouble with a update cursor loop.

"Property_Layer" is a feature layer and I want to narrow the arcpy.UpdateCursor to empty "LOCALITY" fields. I then want to use the for loop to set the "LOCALITY" field to the variable "value".

my code stalls at the rows.updatRow(row) line. I'm not sure I can use a feature layer with the UpdateCursor....!?

I am new to this so any help would be greatly appreciated!

    rows = arcpy.UpdateCursor ("Property_Layer",'"LOCALITY" = ' + "'" + "'")

    row = rows.next()

        for row in rows:
            row.setValue ("LOCALITY", value)
            rows.updateRow(row)

            del row, rows   #delete cursors

Re: need help with UpdateCursor and .updateRow(row)!!!

AndrewWickham — Tue, 21 May 2013 14:37:12 GMT

P.S the indenting on my code is correct, not like what is shown in my first post.

thanks!

Andrew

Re: need help with UpdateCursor and .updateRow(row)!!!

ChrisSnyder — Sun, 12 Dec 2021 06:35:35 GMT

I think it would look more like this:

value = "CAT"
rows = arcpy.UpdateCursor ("Property_Layer","LOCALITY = '' OR LOCALITY IS NULL") #blank string or Nulls
for row in rows: 
   row.setValue("LOCALITY", value) #assuming this is a text field
   rows.updateRow(row)
del row, rows

Re: need help with UpdateCursor and .updateRow(row)!!!

ThaiTruong — Sun, 12 Dec 2021 06:35:38 GMT

Here is the correct syntax to create an update cursor to help you started

import arcpy

def UpdateField(value):
    # Create update cursor for your feature class
    # Update the correct path to your feature layer
    rows = arcpy.UpdateCursor(r"C:\Temp\test.gdb\Property_Layer")

    # Update/calculate field to the variable "value"
    for row in rows:
        # Update "LOCALITY" Field
        row.LOCALITY= value
        rows.updateRow(row)
    # Delete cursor and row objects to remove locks on the data
    del row
    del rows

Then you can call this UpdateField() function and pass a variable with a value that you want to calculate the field to.

Re: need help with UpdateCursor and .updateRow(row)!!!

T__WayneWhitley — Tue, 21 May 2013 19:42:08 GMT

I think Chris meant to indent the line for updateRow...

Re: need help with UpdateCursor and .updateRow(row)!!!

ChrisSnyder — Tue, 21 May 2013 20:31:44 GMT

Woops - yes - correcting that now.