topic Python Script: Create separate feature classes for each record in shapefile in Geoprocessing Questions

Python Script: Create separate feature classes for each record in shapefile

MarkNorris-Rogers — Tue, 28 May 2019 13:12:30 GMT

Dear Forum Members,

I need to create a separate feature class from each record in a shapefile
(i.e. each row in original shapefile needs to be a new feature class in its own right).
I need to name each new feature class by its ID number from the AWS_ID field in the original shapefile
See Python script below:

1.#Import required modules
2.import arcpy, os, traceback
3.from arcpy import env
4.
5.env.workspace = r"C:\temp\"
6.env. overwriteOutput = True
7.
8.# Script arguments
9.awsInput = r"C:\Temp\AWS.shp"
10.awsName = "AWS_ID" # Field in AWS.shp to be used as name for output shpfile
11.cursor = arcpy.SearchCursor(awsInput)
12.
13.for aws in cursor:
14. awsID = aws.getValue(awsName)
15. awsName = "{}_AWS".format(aws)
16. arcpy.CopyFeatures_management(awsInput, r"C:\Temp\DataExtract_Work.gdb\awsName", "0", "0", "0")

(NB. line numbers will affect indentation!)

I have tried to get it working by
a) searching the arcpy help - source of line 11, SearchCursor
b) reviewing Esri online Python courses I have done - source of line 15
c) viewing online video tutorials on ModelBuilder iteration

Before I added lines 14,15 but ran line 16,the script ran but either overwrote all but the last record or
added all the records as per the original shapefile. Currently I get a RuntimeError: ERROR 999999,
referring to line 14. Prior to adding lines 15-16, and having a print aws.getValue(aws) statement,
it printed out each ID number on a separate line.

Question 1. Where have I messed up?

Question 2. Does one have to first create a list if one is only using a single feature class/shapefile as the input?

Any help will be appreciated.

Kind regards,
Mark

Re: Python Script: Create separate feature classes for each record in shapefile

JoeBorgione — Sun, 12 Dec 2021 02:18:28 GMT

First, use the arcpy.da.SearchCursor. It's faster and more reliable. One thing you seem to be missing is a selection statement. You'll need that to isolate each record. In order to make a selection, you'll need to use arcpy.MakeFeatureLayer().

Psuedo code:

import arcpy
arcpy.MakeFeatureLayer('yourFeatureClass', 'layerName')

fields = ['OBJECTID', 'YourNeededFields']

with arcpy.da.SearchCursor('layerName,fields) as cursor:
  for row cursor:
     arcpy.SelectLayerByAttribute_management('layerName','NEW_SELECTION','OBJECTID = 
     {}.format(row[0])
     arcpy.CopyFeatures_management('layerName','YourOutFeatureClass')‍‍‍‍‍‍‍‍‍‍

Re: Python Script: Create separate feature classes for each record in shapefile

Egge-Jan_Pollé — Tue, 28 May 2019 14:57:51 GMT

Hi Mark Norris-Rogers‌,

You might also have a look at this discussion, and at the answers given there: arcpy - Loop for exporting shapefiles from an existing shapefile - Geographic Information Systems Stack Exchange

HTH,

Egge-Jan

Re: Python Script: Create separate feature classes for each record in shapefile

MarkNorris-Rogers — Tue, 28 May 2019 15:15:57 GMT

Hi Joe,

Thanks very much for your help. I did wonder about a select statement but the example code I looked at did not seem to use one - obviously I was looking at the wrong thing! I will apply your suggestions.

Thanks again,

Mark

Re: Python Script: Create separate feature classes for each record in shapefile

MarkNorris-Rogers — Tue, 28 May 2019 15:17:04 GMT

Hi Egge-Jan,

Thanks very much. I will look up that link.

Kind regards,

Mark

Re: Python Script: Create separate feature classes for each record in shapefile

Luke_Pinner — Mon, 03 Jun 2019 03:18:35 GMT

Have you considered the split by attributes tool? Split By Attributes—Help | ArcGIS Desktop

Re: Python Script: Create separate feature classes for each record in shapefile

NeilAyres — Mon, 03 Jun 2019 10:01:15 GMT

Perhaps the real question here is "why would you do that?". Very strange.

Re: Python Script: Create separate feature classes for each record in shapefile

NeilAyres — Mon, 03 Jun 2019 10:02:37 GMT

I have seen many projects in the past which contain thousands of shapefiles, which actually should be consolidated into one feature with an attribute indicating what is what.

Re: Python Script: Create separate feature classes for each record in shapefile

Luke_Pinner — Mon, 03 Jun 2019 11:08:24 GMT

Sometimes it's necessary. When the consolidated database is just too big and unwieldy to use, even with spatial and attribute indexes and professional database tuning there's no other option. Think continental scale cadastre, tenure, species distributions. Definition queries just don't cut it in these cases.

Re: Python Script: Create separate feature classes for each record in shapefile

MarkNorris-Rogers — Mon, 03 Jun 2019 13:03:06 GMT

Hi Luke,

Thanks for this suggestion. I was not aware of this tool, but it looks like it will be of help.

Kind regards,

Mark

Re: Python Script: Create separate feature classes for each record in shapefile

MarkNorris-Rogers — Mon, 03 Jun 2019 13:09:10 GMT

Hi Neil,

The client requires a separate table of attributes for each record in the point file. For each point, data needs to be extracted from a number of separate raster files to provide a record of all the raster attributes for that point, hence the need to break up the point data.

Thanks,

Mark

Re: Python Script: Create separate feature classes for each record in shapefile

DuncanHornby — Thu, 06 Jun 2019 08:58:52 GMT

I agree with Neil Ayres‌ to explode out your data into individual shapefiles does seem a little "excessive". Going down that road incurs all sorts of file management issues where a single cursor feeding out your point for the raster processing would be much more sensible and efficient, unless its an issues with some sort of mega dataset as Luke suggested? I would be going back to the client and challenging them to understand why they really need it in that format and see if they could not adapt/improve their workflow.

If turns out they are using ArcView 3.2 on a windows XP machine with 8MB of ram then fair enough...

Re: Python Script: Create separate feature classes for each record in shapefile

JoeBorgione — Thu, 06 Jun 2019 13:44:49 GMT

If turns out they are using ArcView 3.2 on a windows XP machine with 8MB of ram then fair enough...

This wouldn't be so funny if it weren't so true...