topic Re: Editing shapefile with Python in Python Questions

Editing shapefile with Python

João_PauloPereira — Fri, 11 Apr 2014 12:52:32 GMT

I'm new here at the Forum and I tried looking for something like my problem, and I got nothing. If there is something, please, forgive me.

I have a binary polygon shapefile, with a feature called GRIDCODE with 0s and 1s for earch polygon.
I want to edit this shapefile and delete every polygon with the number 1. In other words, I want only the polygons with GRIDCODE number 0 in my shapefile. To do that in Editor mode is quite simple, but I want to do it through a python code. Does anymore here know how to do it?

Thanks

Re: Editing shapefile with Python

IanMurray — Fri, 11 Apr 2014 13:01:40 GMT

I'd probably use an update cursor to evaluate the value of the field, then delete the row if it the field value equals 1. If you need some starter code let me know.

Re: Editing shapefile with Python

João_PauloPereira — Fri, 11 Apr 2014 17:00:33 GMT

I'd probably use an update cursor to evaluate the value of the field, then delete the row if it the field value equals 1. If you need some starter code let me know.

iamurray, thanks for the help. If you could send me the code I would appreciate. I'm new using python in ArcGIS, so every help is welcome.

Thanks

Re: Editing shapefile with Python

IanMurray — Sun, 12 Dec 2021 02:02:27 GMT

import arcpy
from arcpy import env

env.workspace = #"put the file path to the folder your shapefile is in here as a string"

cursor =  arcpy.da.UpdateCursor(#"shapefile name" , "Field name that has the 1's and 0's")
    
for row in cursor:
    if row[0] == 1:
        cursor.deleteRow()

del row 
del cursor

I'd make a copy of your shapefile first to test this on, there is no way to undo the delete row, so I would test it on the copy before applying it to the actual file.

Re: Editing shapefile with Python

João_PauloPereira — Sun, 12 Dec 2021 02:02:30 GMT

import arcpy
from arcpy import env

env.workspace = #"put the file path to the folder your shapefile is in here as a string"

cursor =  arcpy.da.UpdateCursor(#"shapefile name" , "Field name that has the 1's and 0's")
    
for row in cursor:
    if row[0] == 1:
        cursor.deleteRow()

del row 
del cursor
I'd make a copy of your shapefile first to test this on, there is no way to undo the delete row, so I would test it on the copy before applying it to the actual file.

Ok...I'll try. Thanks

Re: Editing shapefile with Python

Luke_Pinner — Sun, 13 Apr 2014 10:24:44 GMT

Use arcpy.SelectLayerByAttribute_management then arcpy.DeleteFeatures_management

Code examples are in the help:
http://resources.arcgis.com/en/help/main/10.2/index.html#//001700000071000000
http://resources.arcgis.com/en/help/main/10.2/index.html#//001700000036000000

Re: Editing shapefile with Python

João_PauloPereira — Thu, 17 Apr 2014 10:41:28 GMT

Use arcpy.SelectLayerByAttribute_management then arcpy.DeleteFeatures_management

Code examples are in the help:
http://resources.arcgis.com/en/help/main/10.2/index.html#//001700000071000000
http://resources.arcgis.com/en/help/main/10.2/index.html#//001700000036000000

Thanks for the answer again Ipinner...
Your tip worked perfectly. The code turned like this:

arcpy.SelectLayerByAttribute_management ("GAP", "NEW_SELECTION", " GRIDCODE=1 ")
arcpy.DeleteFeatures_management("GAP")

Quite easy and everything worked really nice...