topic Re: How to get field values from every feature, and place them in a comma seperated string? in Geoprocessing Questions

How to get field values from every feature, and place them in a comma seperated string?

MichaelKowalczyk — Sat, 11 Dec 2021 06:55:47 GMT

Hello, I have a modelbuilder tool with an iterator that produces a selection in another feature class each iteration. I would like to get the value of a field from the records in each selection, and put them in a coma separated string.

I have attempted to use an embedded python tool to use a search cursor over these records, but it does not seem to work. I get a runtime error: cannot open '<<field name>>'

Do you have any suggestions as to how to accomplish this? Would a searchcursor work in an iterator model? Thank you.

My python tool containing the search cursor. It works as expected in isolation, but not in the model builder tool.

import arcpy
from arcpy import env
env.workspace = arcpy.GetParameterAsText(0) 

##import time
#from datetime import datetime

##current_time=time.strftime("%H:%M:%S")+" "+ time.strftime("%d/%m/%Y")


local_pairlist = "" #list will be populated with pair ids from paths in prevailing direction

#selected features

pathfc      = arcpy.GetParameterAsText(1)  #demand paths in prevailing direction

path_pair_id= str(arcpy.GetParameterAsText(2)) #pair id field


with arcpy.da.SearchCursor(pathfc,(path_pair_id,)) as path_cursor:


                
        newpair=path_row[0] 

        if local_pairlist == "":
            local_pairlist+=newpair
        else:
            local_pairlist+=r","+newpair
       
                
    #--//colection loop--#   

##print "OD Builder Finished!\n\nOutput table="+str(out_name)+"\n\nLocation: " + str(out_path)


arcpy.AddMessage("Subpairs saved!")
arcpy.SetParameter(3, local_pairlist)

Re: How to get field values from every feature, and place them in a comma seperated string?

NeilAyres — Sat, 06 Feb 2016 06:51:21 GMT

I normally do more complex stuff like this in python.

So, could you show us your code?

Re: How to get field values from every feature, and place them in a comma seperated string?

WesMiller — Sat, 11 Dec 2021 06:55:50 GMT

Yes a search cursor will work in a model with an iterator in it.

Here's a picture of the model i tested with:

Here's the code used:

import arcpy


#Variables
fc = arcpy.GetParameterAsText(0)
fld = arcpy.GetParameterAsText(1)


mystring = ""
with arcpy.da.SearchCursor(fc,fld) as cursor:
    for row in cursor:
        mystring += str(row[0]) +","


arcpy.AddMessage(mystring[:-1])

Re: How to get field values from every feature, and place them in a comma seperated string?

MichaelKowalczyk — Sat, 06 Feb 2016 20:48:58 GMT

Thank you, Wes Miller, for confirming that it should work. My tool looked very much like yours. However, I was getting an error that it could not open the specified field. Do you have any suggestions?

Re: How to get field values from every feature, and place them in a comma seperated string?

WesMiller — Sat, 06 Feb 2016 22:12:28 GMT

Could you post the error you are getting. Have you confirmed the field name exists? Could you also post the model you are using

Re: How to get field values from every feature, and place them in a comma seperated string?

MichaelKowalczyk — Sat, 06 Feb 2016 22:59:25 GMT

I actually ended up rewriting the tool from scratch in Python, and actually got at least a 10 fold improvement in performance!

Re: How to get field values from every feature, and place them in a comma seperated string?

MichaelKowalczyk — Sat, 06 Feb 2016 23:02:54 GMT

I was using an unwieldy model that I should have written in arcpy to begin with. I actually managed to do so in a relatively quick manner, it works 10-100 x faster than model builder! Troubleshooting it seems no longer necessary.

Re: How to get field values from every feature, and place them in a comma seperated string?

NeilAyres — Mon, 08 Feb 2016 08:22:08 GMT

Yes,

there have been other post here about the speed improvements once a task is coded using arcpy / python.

Good to see you have your solution.