0
votes
1answer
68 views

Using Python for Polygon Neighbors Analysis in ArcGIS 10.1: Script producing erroneous results

I'm struggling with a python script that is supposed to calculate a field for a polygon feature class. The calculation is of the average of a field value (P_TOT_DEV) for each of a given polygon's ...
9
votes
5answers
304 views

How to improve performance when using ArcGIS cursors in Python with big tables?

I have a pretty big point feature class in a file geodatabase (~4 000 000 records). This is a regular grid of points with a 100m resolution. I need to perform a kind of generalization on this layer. ...
1
vote
1answer
154 views

Insert Cursor fails to write results to table

Insert Cursor fails to write results to table. The Search Cursor is returning the results, but errors when trying to insert into field. # Insert Cursor for GDB table to GDB table # Import modules, ...
2
votes
1answer
123 views

Why cant I use SelectLayerByAttribute_management while a cursor is set

I've been having a problem with arcpy in that the simple line: arcpy.SelectLayerByAttribute_management ("TEMP_LINES") produces this response: Runtime error : ERROR 000358: Invalid expression Failed ...
1
vote
0answers
18 views

Q: cursor memory and fields therein

Theoretical Python question. Say you have an update cursor while-loop for a few selected records. While looping through the rows, at some point a nested if statement triggers an "addfield" event. The ...
3
votes
2answers
131 views

arcpy.SearchCursor loops one time but then does not repeat

The part of the script I'm having trouble with is the arcpy.SearchCursor. The cursor runs 1x and then does not re-run. The goal was to re-retrieve the field value and apply it to the image layout. It ...
3
votes
1answer
233 views

set values in feature class attribute table to null

I've created a point-data featureclass (fc) containing data from a simple .txt file using Arcpy as follows: arcpy.CreateFeatureclass_management(out_path= outPath, out_name= 'fcTest', geometry_type= ...
1
vote
0answers
153 views

Only perform Near analysis on selected rows

I am writing a Python script to perform a near analysis on features from two different shapefiles with common attributes. This is happening in a Search Cursor. However, whenever I tried to use the ...
1
vote
1answer
130 views

Updating the value of a field with pre-defined values

I am trying change the value of a row for a field whose type is "short" in arcmap using a python script. with arcpy.da.UpdateCursor(FILENAME, FIELD) as cursor: for row in cursor: row = ...
1
vote
1answer
42 views

Deleting the cursor object

Can someone explain why you need to delete the cursor objects and the iterator when you use for example: arcpy.UpdateCursor(blah) I've checked the esri docs and there doesn't seem to be an ...
3
votes
2answers
308 views

Move the cursor backward - opposite of row = rows.next()

I'd appreciate if anyone could please tell me if there is a way to go up one row in python cursor. opposite of row = rows.next() Thank you!
2
votes
2answers
321 views

Field calculator or update cursor?

I have a feature class in which one field (let's call it "Field_A"), as yet empty, is to be populated by the contents of another field ("Field_B") multiplied by a certain number (I'll call it the ...
4
votes
3answers
352 views

How to create Where Clause from user input via Python list?

I am trying to perform a query based on values in a Python list. The where clause will then be used in an Update Cursor, so that the rows NOT equal to the values in the list will be deleted. This is ...
2
votes
1answer
310 views

Am I over-complicating adding and then calculating fields? Suggestions for a better way? (Python)

I'm attempting to re-position a question I asked yesterday here. I am starting to think that the way I wrote my code just isn't the best way. Am I overcomplicating things? I know for a fact that ...
3
votes
1answer
565 views

Incorrect field name resulted in RuntimeError: ERROR 999999 (Also, better code for adding and calculating fields)

This is the bottom half of my code (and it's been edited somewhat to share publicly). The code works perfectly fine when the fieldList has only three fields in it, but when I populate it with all 108 ...
2
votes
2answers
223 views

Using select by location to update a field in a feature class

I am using Arc 10.1 and I am working on a script that takes a value from a field within one shape file and updates a field in another shape file based on its location. Basically I have smaller parcels ...
2
votes
1answer
138 views

Updating and inserting a field within the same loop

I am working with an empty feature class where I am writing a script to create polylines within the featureclass and attach an associated text value with the polyline. I am using a for loop as noted ...
1
vote
2answers
185 views

Batch set value/calculate field inside Cursor

I am matching data using a cursor, where one of the final steps is filling in a new attribute, match, with a value calculated during the cursor. This matching is done to an ID field in the original ...
2
votes
1answer
305 views

How to use ArcPy cursor to define each feature sequentially as current selection of layer?

I want to implement a script that runs through each feature of a feature class, zooms to the extent of the feature, sets the scale to 1:5.000 and adjacent takes a picture of the scene. The steps are ...