topic Re: My python script calculates only the value of the immediate previous record in Python Questions

My python script calculates only the value of the immediate previous record

OLANIYANOLAKUNLE — Sat, 11 Dec 2021 15:37:49 GMT

My python script calculates only the value of the immediate previous record instead of calculating the values of all preceding records before that particular record. The example (the image) below is the undesired output;

While the image below here is what i want to achieve;

This is my python script i used;

import arcpy
from arcpy import da
CensusBldForm = "CensusBldForm"
Calculated_EA1=0
with arcpy.da.UpdateCursor(CensusBldForm, ["OBJECTID", "EstimatedPopulationinEA", "Calculated_EA"]) as cursor:
     for row in cursor:
          Calculated_EA2 = row[1]
          row[2] = (Calculated_EA1 + Calculated_EA2)
          Calculated_EA1 = Calculated_EA2
          cursor.updateRow(row)

Kindly assist me with the above please.

Re: My python script calculates only the value of the immediate previous record

WesMiller — Tue, 26 Apr 2016 18:34:25 GMT

Change this line

Calculated_EA1 = Calculated_EA2

To this

Calculated_EA1 += Calculated_EA2

Re: My python script calculates only the value of the immediate previous record

OLANIYANOLAKUNLE — Tue, 26 Apr 2016 19:30:58 GMT

Thanks, it worked like magic

Re: My python script calculates only the value of the immediate previous record

WesMiller — Tue, 26 Apr 2016 19:42:22 GMT

That's great! Please remember to mark your question as answered

Re: My python script calculates only the value of the immediate previous record

OLANIYANOLAKUNLE — Tue, 26 Apr 2016 21:38:08 GMT

My edits don't get saved after running the script, because i have to start an edit session before running the script;

CensusBldForm = "CensusBldForm"

Calculated_EA1=0

with arcpy.da.UpdateCursor(CensusBldForm, ["OBJECTID", "EstimatedPopulationinEA", "Calculated_EA"]) as cursor:

for row in cursor:

Calculated_EA2 = row[1]

row[2] = (Calculated_EA1 + Calculated_EA2)

Calculated_EA1 += Calculated_EA2

cursor.updateRow(row)

What do you think might be wrong or better still can i get it to run without starting an edit session i.e using a arcpy.UpdateCursor instead of arcpy.da.UpdateCursor? Thanks

Re: My python script calculates only the value of the immediate previous record

OLANIYANOLAKUNLE — Tue, 26 Apr 2016 22:12:39 GMT

This is the error message i get when i want to save edits;

Kindly assist me please. Thanks in advance

Re: My python script calculates only the value of the immediate previous record

DanPatterson_Retired — Tue, 26 Apr 2016 22:19:16 GMT

a wild guess that you aren't doing this on a file stored on your local machine but from sde or some other thing like that. That error message has a history... there are some suggestion which you can search on geonet and narrow down the issue. This is just one of several

https://community.esri.com/message/551258#comment-551258

Re: My python script calculates only the value of the immediate previous record

OLANIYANOLAKUNLE — Tue, 26 Apr 2016 22:20:22 GMT

Thanks, i'm actually running my script against an SDE Geodatabase

Re: My python script calculates only the value of the immediate previous record

DanPatterson_Retired — Tue, 26 Apr 2016 22:26:38 GMT

that is bad to hear from the threads... good luck

Re: My python script calculates only the value of the immediate previous record

OLANIYANOLAKUNLE — Tue, 26 Apr 2016 22:29:33 GMT

Thanks i changed from the default version to another version and i didn't get any error and my edits where retained as well.

Re: My python script calculates only the value of the immediate previous record

OLANIYANOLAKUNLE — Wed, 27 Apr 2016 01:16:45 GMT

Thanks