topic Re: Converting Arcade Script to Python in ArcGIS Pro Questions

Converting Arcade Script to Python

CaitlinSjodin — Mon, 29 Jul 2024 17:05:13 GMT

Hi all,

This feels like a problem that should have a really straightforward solution but for some reason I can't wrap my head around it. I have a simple arcade script that was given to me that was used in the Calculate Field window. I'm trying to take that expression and incorporate it into a python script in jupyter notebook.

This is the arcade script:

var LINED = $feature.LINED
var startDate = IIf(LINED == "Yes", Date($feature.LINEDYEAR), Date($feature.INSTALLDATE));
var endDate = Now();
var age = round(DateDiff(endDate, startDate, 'years'),2);
return age;

It's being used to populate a field called AGE_YEARS

Basically I need a python script that says:

If (LINED == 'Yes'): # Calculate AGE_YEARS to be the difference between LINEDYEAR and the current date else: # Calculate AGE_YEARS to be the difference between INSTALLYEAR and the current date # Below is what I have so far from datetime import datetime edit_layer = "AIRDRIE_EDIT.GIS.sGravityMain" LinedDate = !LINED_YEAR! InstallDate = !INSTALL_DATE! CurrentDate = datetime.now() diff1 = CurrentDate - LinedDate diff2 = CurrentDate - InstallDate AgeYears = "getClass(!LINED!)" # Criteria for how to calculate field codeblock = """ def getClass(LINED): if (LINED == 'Yes'): return diff1 else: return diff2""" # calculate age in years arcpy.management.CalculateField(edit_layer, 'AGE_YEARS', AgeYears, "PYTHON3", codeblock)

The above block shows what I have so far. Any suggestions are appreciated!

Re: Converting Arcade Script to Python

Ed_ — Mon, 29 Jul 2024 17:06:37 GMT

This might help Populating field based on value of another field

Maybe something like the following:

AGE_YEARS = reclass(!LINED!) def reclass(LINED): if(LINED == "YES": return !LINEDYEAR! - !CURRENTDATE! else: return !INSTALLYEAR! - !CURRENTDATE!

Re: Converting Arcade Script to Python

CaitlinSjodin — Mon, 29 Jul 2024 17:13:21 GMT

Thanks for the suggestion! I've tried something similar (I've edited my post above to show the code) and I'm getting this error:

TypeError: unsupported operand type(s) for -: 'datetime.datetime' and 'SList'

Re: Converting Arcade Script to Python

Ed_ — Mon, 29 Jul 2024 17:29:29 GMT

That's a datatype support error

Maybe look into this and this

Re: Converting Arcade Script to Python

CaitlinSjodin — Mon, 29 Jul 2024 20:31:20 GMT

Thanks for the help, the issue seemed to be that the script wasn't recognizing the field name as the field, instead it seemed to just be reading it as a string. I couldn't figure it out and I ended up going down a rabbit hole that lead me to using an updatecursor instead. I've listed the code below, hopefully it helps someone.

import arcpy from datetime import datetime # Layer being edited edit_layer = "SanMain" # Fields being used in the updatecursor fields = ['LINEDYEAR', 'INSTALLDATE', 'AGE_YEARS', 'LINED'] #Variable showing current date CurrentDate = datetime.now() # Update cursor to run through layer and update the AGE_YEARS field with the difference between now and lined or install date with arcpy.da.UpdateCursor(edit_layer, fields) as cursor: for row in cursor: if (row[3] == 'Yes'): row[2] = round(((CurrentDate - row[0]).total_seconds())/(365.25*24*60*60),2) elif (row[3] == 'No' or row[3]== None): row[2] = round(((CurrentDate - row[1]).total_seconds())/(365.25*24*60*60),2) cursor.updateRow(row)

Re: Converting Arcade Script to Python

clt_cabq — Mon, 29 Jul 2024 21:23:17 GMT

I suspect the solution could be using an update cursor (update cursor documentation) - that will go row by row through your data, evaluate the conditions you are testing for, then apply a change in the target field. The form of this would look something like this, this is very back of the napkin sketched out here, so you'll have to work through it and there are probably much more elegant ways to handle this.

fc = path name to your feature class to update fields = list of fields you need ['LINED','AGE_YEARS'] with arcpy.da.UpdateCursor(fc,fields) as cursor: for row in cursor: if row[0]== 'Yes': lined_date = <calc to get diff1 in your example> row[1] = lined_date elif row[0]<> 'Yes': lined_date = <calc to get diff2 in your example> row[1] = lined_date cursor.updateRow(row)