topic Re: Calculate Field with Python in ArcGIS Pro Questions

Calculate Field with Python

KalSsin — Wed, 24 Mar 2021 11:32:16 GMT

uniqueList = []

def isDuplicate(inValue):

if inValue in uniqueList:

return 1

else:

uniqueList.append(inValue)

return 0

Hi~~~Please refer to the illustration.

Above coding to output 0 1.
I'd like to output 1 1.

Re: Calculate Field with Python

DavidPike — Wed, 24 Mar 2021 11:35:36 GMT

Which field are you calculating on? Also unsure of the logic of that code compared to your expected output - doesn't make sense to me.

Anyway, as the code is executed on a per-row basis with the function, unique_list would have to be set to a global.

uniqueList = [] def isDuplicate(inValue): global uniqueList if inValue in uniqueList: return 1 else: uniqueList.append(inValue) return 0

Re: Calculate Field with Python

KalSsin — Wed, 24 Mar 2021 12:00:30 GMT

Thank you for your reply.

Re: Calculate Field with Python

DavidPike — Wed, 24 Mar 2021 12:08:18 GMT

Are you saying the top picture is what you want - that makes sense to me - rather than the bottom picture?

looking at the code, I don't see how you got those results in the bottom picture either. Did you try the code I suggested?

Re: Calculate Field with Python

KalSsin — Wed, 24 Mar 2021 12:13:42 GMT

I used your code.

The picture below is the printout I want. I used your code.

I'd like to express all duplicate names by 1.

Re: Calculate Field with Python

KalSsin — Wed, 24 Mar 2021 12:15:17 GMT

Re: Calculate Field with Python

DavidPike — Wed, 24 Mar 2021 12:32:19 GMT

I'd probably run a searchCursor to generate a list of unique values, then run the field calculator using that list of pregenerated unique values.

Re: Calculate Field with Python

KalSsin — Wed, 24 Mar 2021 12:44:09 GMT

Thank you for your reply.

Re: Calculate Field with Python

JakeSkinner — Wed, 24 Mar 2021 13:01:10 GMT

It may be easier to do this with a script rather than the Field Calculator. Ex:

import arcpy table = r"C:\TEMP\PYTHON\Test.gdb\XY" nameDict = {} with arcpy.da.SearchCursor(table, ["NAME"]) as cursor: for row in cursor: if row[0] not in nameDict.keys(): nameDict[row[0]] = 0 else: nameDict[row[0]] = 1 del cursor with arcpy.da.UpdateCursor(table, ["NAME", "Field"]) as cursor: for row in cursor: row[1] = nameDict[row[0]] cursor.updateRow(row) del cursor

Result: