Cursors are used by database programmers to process individual rows returned by database system queries.

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17
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4k views

Exporting table to XYZ ASCII file via ArcPy?

I'm looking for a way to export an ArcGIS table (created with the Sample tool) to a text file via ArcPy. I can do this in ArcGIS via the context menu by right-clicking the table, but have not found ...
14
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2answers
1k views

How is the data access cursor performance so enhanced compared to previous versions?

The data access module was introduced with ArcGIS version 10.1. ESRI describes the data access module as follows (source): The data access module, arcpy.da, is a Python module for working with ...
10
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5answers
781 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. ...
8
votes
4answers
3k views

Accessing attribute table within shapefile and replace values?

I would like to find a Python script that will access an attribute table within a shapefile and either update or replace records inside a field column. More specifically, I would like to use the ...
7
votes
2answers
2k views

Getting unique value of second field using arcpy.da.SearchCursor?

I have a feature class and using arcpy.da.SearchCursor I'm getting unique values of a field (e.g. Name). How can I use this method to get the associated row value of a different field (diff field = ...
6
votes
5answers
472 views

How to access adjacent rows with cursor?

In the attached screenshot, the attributes contain two field of interest "a" and "b". I want to write a script to access the adjacent rows in order to make some calculations. To access a single row, ...
6
votes
3answers
970 views

Zero filling attributes using ArcPy/Python?

I am just learning python and I need to convert a 2 digit numeric attribute in a table to a 2 digit zero-filled attribute in a script. For example, 9 needs to be 09.
6
votes
2answers
2k views

How to create an offset polyline in arcpy?

I am trying to create an offset polyline using arcpy, identical to the function in ArcObjects (constructoffset). After trying to access ArcObjects in arcpy, which I found difficult for those not ...
6
votes
1answer
486 views

How to add Attributes to a polygon with arcpy

I have a question about arcpy. I want to create a polygon FeatureClass with attributes. The code below is just test-code that generates some polygons for speed testing. I want to add some additional ...
6
votes
2answers
323 views

What technology is used behind arcpy cursors?

I'm using ArcGIS Server 10.0. I have a geoprocessing using arcpy search, update and insert cursors. I'd like to know more about the technology behind these cursors. Does it use any driver or pool to ...
5
votes
1answer
137 views

UpdateCursor gives Too few parameters Expected 1?

Can anyone tell me why my script isnt working? I cant figure out where I went wrong. I am working with an access personal geodatabase. Adding a field, then updating that field with yes if the field ...
5
votes
1answer
866 views

“Sequence size” doesn't match row in Python?

Essentially I am trying to calculate a value for a couple of fields after adding them. Below you can see how I am adding the fields and then an example on how my "for" statement is looping through the ...
5
votes
1answer
2k views

Is it possible to sort an arcpy.da.UpdateCursor()?

I have an ArcPy Data Access update cursor that I would like to sort before making updates to it. The cursor makes updates if I don't sort, but if I add a sort to the cursor I get an error, ...
5
votes
1answer
225 views

need to find max value among fields AND PRINT FIELD NAME

I have a Census dataset that contains eight fields with percentages. I would like a python script that finds the highest value between the eight fields, but also tells me which field the highest ...
5
votes
3answers
3k views

Debugging RuntimeError: workspace already in transaction mode from arcpy.da.UpdateCursor and ArcSDE feature classes?

I am making my first attempt at editing an ArcSDE feature class with python through a da.UpdateCursor. I'm essentially taking code I've written for a file geodatabase feature class and applying it to ...
5
votes
2answers
2k views

How to replace arcpy.CalculateField_management with an update cursor?

I'd like to replace this expression arcpy.CalculateField_management(bufferFile, "Shape_Area", "float('!shape.area@squaremeters!')", "PYTHON") with an arcpy.da.updatecursor. The reason for this is ...
5
votes
1answer
866 views

Deleting file locks in ArcPy?

I did not realize that I should have been deleting cursors after accessing attribute tables until today. Up until now I never did this, but I've noticed that there are lots of file locks after my ...
5
votes
1answer
2k views

Updating point geometry based on geometry of another feature class using arcgisscripting?

I'm looking to update the point geometry of lets say "oldFC" by obtaining the shape geometry of "newFC" and applying that to the "oldFC". I also want it to grab the value in the ID field in ...
5
votes
1answer
86 views

Writing points to a file

Trying to write the city name and point coords to a file. The following works with a polygon shapefile but not the point shapefile. I know I'm missing something basic. import arcpy # Set up the ...
4
votes
3answers
363 views

Why [0] is needed in row[0] when using ArcPy (Data Access) cursors?

when running the following 2 sample codes, "[0]" is needed to be added after "row" in order to make code run well. I was confused. can anyone help explain? I know that it might be too easy for most of ...
4
votes
2answers
2k views

arcpy.SearchCursor row.var

In arcpy.SearchCursor for row in rows I can return row.fieldname statically, but if fieldname is a variable, I don't know how to return the row.value of that variable dynamically. for example: ...
4
votes
3answers
554 views

Using da.SearchCursor to get count of unique values in a field

Is it possible to use arcpy.da.SearchCursor() to get a count of unique features in a field without a dictionary? So, by this I mean if I have a field called TEXT which contains 10,000 rows populated ...
4
votes
2answers
413 views

Is it a bad idea to convert a File Geodatabase table to a dictionary?

First, what am I trying to do? I am building a Python script that should be called from an ArcMap 10.0 toolbox. This scripts uses (among other inputs) data contained in huge gdb tables. It processes ...
4
votes
3answers
942 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 ...
4
votes
2answers
2k 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= ...
4
votes
1answer
572 views

Arcpy.da.UpdateCursor, Error - Sequence size must match size of row

I am trying to use an UpdateCursor fill in a field but I keep getting an error, can anyone tell me what I am doing wrong? My code is below: import arcpy fc= "C:\Users\Keri\Desktop\GEP_690\Project ...
4
votes
1answer
169 views

Generic error on an “if” in arcpy

My code has to check if a value in a shapefile attribute table belongs to a certain group of landuses. Below I paste my code: cursor = arcpy.SearchCursor(buf_intersect) fields = ["GTYS_Branc", ...
4
votes
1answer
92 views

How to delete rows in attribute table of a shape file based on specific condition?

I want to delete ceratin rows in a shape file if field ID is equal to certain number (say 2). Below is what I am trying, import arcpy shape="C:\Users\Data\Loc.shp" rows = ...
4
votes
3answers
3k views

How to extract data using arcpy.da.SearchCursor

I have a shapefile of point features showing fire locations in a given year. One of the fields is named "YYYYMMDD" and indicates the corresponding date that that fire happened. In Python, I am trying ...
4
votes
2answers
2k views

Getting XY coordinates and field values for each row in ArcPy SearchCursor?

I am trying to enumerate each row of a points shape file and get a certain field's value (elevation) and the xy coordinates. But I see I can only use: arcpy.SearchCursor to get the field; OR ...
4
votes
2answers
3k views

Getting values from attribute table and inserting another table using ArcPy?

I have line feature class of a river network and “FromTo” table. Lines are dissolved so they are not segmented from junctions. I need to write a Python script in ArcGIS to do following: Begin from ...
4
votes
2answers
112 views

Python script that creates polygon feature class with given coordinates

Write a script that creates a new polygon feature class containing a single ( square ) polygon with the following coordinates: ( 0, 0 ), ( 0, 1,000 ), ( 1,000, 0 ), and ( 1,000, 1,000 ). ...
4
votes
2answers
2k views

insert cursor “Row contains a bad value”

I'm having a problem copying data from a shapefile to a feature class using an insert cursor. Here is the part that is causing trouble: newRows = arcpy.InsertCursor(Target) sourceRows = ...
4
votes
1answer
48 views

Update row with next row's value

I am trying to extract the endpoint of a line with very fine scale and overlapping GPS data. I would normally just use the locn_id+1 but that doesn't work because the data were originally rarified. ...
4
votes
1answer
409 views

Counting and storing events contained within polygon using ArcPy?

I have a fairly large project and I would like to automate some tasks using Python. Problem is, I don’t have any experience with Python for ArcGIS. And I rarely use ArcGIS until something big like ...
4
votes
1answer
595 views

How to extract certain values from a table using the SearchCursor Tool

I am trying to write a python script to extract certain values from a table: the table I am referring to is a big collection of nitrate values for different water depths, which are deposited in the ...
4
votes
1answer
235 views

ArcPy script with cursors running slow?

I've got 2 polygons layers (no gaps): IDUs and crops. What I want is to identify the 3 largest crops by % area for each IDU. This seems common enough but I couldn't find a way to do it all using ...
4
votes
1answer
66 views

Error saving object from python script using GetParameterAsText

I have a script that takes in a line, and creates a certain polygon based on this. My code obtaining the input information is as follows: inFC = arcpy.GetParameterAsText(0) hasClearway = ...
3
votes
3answers
2k views

How to create a copy of a feature class that is vertically and horizontally offset by a given distance?

I want to duplicate a polygon feature class and offset all of the polygons by about 10 feet in both the x and y directions. Is this possible to do using arcpy, or are there any geoprocessing tools ...
3
votes
2answers
2k views

Moving cursor backward i.e. opposite of row = rows.next()?

Can anyone tell me if there is a way to go up one row in python cursor? i.e. opposite of row = rows.next()
3
votes
1answer
5k views

Using ArcPy update cursor to replace <Null> value?

I have been combing the help associated with (None) values in arc, and have not been able to solve the following problem: I have a a field with mixed Null and integer values: 0 100 I would like ...
3
votes
1answer
968 views

Arcpy Update Cursor (arcpy.da.UpdateCursor()) not saving changes to 'SHAPE@LENGTH'

Looked around and found other Cursor questions, but nothing dealing with updating 'SHAPE@LENGTH'. I am running ArcGIS 10.2.1 and have a multipoint shapefile that I am grouping into polygons based on a ...
3
votes
3answers
674 views

Convert cursor output to list of geometries

I want to convert all the geometries returned by search cursor to a list. import math import arcpy from arcpy import env env.workspace = r"C:\GIS Data\GIS data_for Maeenul vai" desc = ...
3
votes
2answers
42 views

Search for textbits in QGIS

Is there a way to search for only parts of text in QGIS. Imagine I have a field in my attributetable called myField and I have several entries there, something like This is awesome Even more awesome ...
3
votes
2answers
39 views

Arcpy Update Cursor with Character Length

I am attempting to create an update cursor to concatenate fields of a parcel ID based on the amount of characters in the MAPNO field. This is important because the spacing between MAPNO and LOT of ...
3
votes
1answer
117 views

Append List not working

Trying to create a list of well counts. In the code below, wellCntList only contains the current county count and not a list of ALL the counts. Sure I'm missing something simple. for cname in ...
3
votes
1answer
54 views

How to use search cursor in a given extent

I want to perform a selective search cursor for a feature class for a given extent. I have tried setting env.extent in the below code but it is returning the whole feature class instead of a fixed ...
3
votes
3answers
2k views

How to calculate a value based on another field under arcpy.da.UpdateCursor and cursor.updateRow?

I am trying to do a calculations under arcpy.da.UpdateCursor. I want to calculate the values for the records that have FIPS=06037. I want to take the values from "kg" column and populate the new value ...
3
votes
1answer
285 views

Debugging TypeError: SearchCursor() got unexpected keyword argument in ArcPy script?

I tried to use SearchCursor(points, fields=fieldname) but I get this error: TypeError: SearchCursor() got an unexpected keyword argument 'fields' I'm not sure why this doesn't work. # Local ...
3
votes
3answers
75 views

How to generate a list of unique years from date field?

I have data that was collected over many years and I'd like to be able to run a python script tool in ArcToolbox (ArcGIS 10.1) to get a list of unique years from the date field. I found an example of ...