Updating a newly generated field with an update cursor

DanielFuller — Mon, 14 Jun 2021 13:58:30 GMT

Hello!

I have a dataset containing rural-urban data that I need to process.

my code generates the isUrban field, I then need to use an update cursor to classify that field as "Rural" or "Urban" based off of the RUC11CD field (I'm currently trying to do this as a boolean), if RUC11CD is equal to or greater than "4" it needs to be classified as "Urban" (or true if i stick with boolean) . i've read the documentation on update cursors and watched some videos.

but i've been stuck for 3 days with no idea what i'm doing wrong. my cursor iterates through my table but classifies everything as false (see screenshot). my cursor code currently looks like this

field_Name = "isUrban" field_Nametype = "INTEGER" field_NameVal = arcpy.ValidateFieldName(field_Name) #Adds the new field if it doesn't already exist fList = arcpy.ListFields(fc,field_Name) if not fList: arcpy.AddField_management(fc, field_Name, field_Nametype, "", "", "") sheet = arcpy.management.MakeTableView(Rural) fieldcheck = arcpy.ListFields(sheet, "isUrban") if len(fieldcheck) == 0: arcpy.AddField_management(sheet, "isUrban", 'INTEGER') if len(fieldcheck) == 1: arcpy.DeleteField_management(sheet, "isUrban") arcpy.AddField_management(sheet, "isUrban", 'INTEGER') fields = ["RUC11CD", "isUrban"] # Create update cursor for feature class with arcpy.da.UpdateCursor(Rural, fields) as cursor: for row in cursor: if fields[0] >3: fields[1] = True else: fields[1] = False cursor.updateRow(row)

if i set the new field to be a string and the fields to be 'true' or 'false' as strings the field returns blank cells

Re: Updating a newly generated field with an update cursor

JohannesLindner — Mon, 14 Jun 2021 14:15:25 GMT

# you're checking and changing fields, not row! # if you do this, it should work: for row in cursor: is_urban = row[0] > 3 cursor.updateRow([row[0], is_urban]) # even shorter: for row in cursor: cursor.updateRow([row[0], row[0] > 3])

# Also: you can replace lines 6 to 16 with this try: arcpy.management.DeleteField(fc, "isUrban") except: pass arcpy.management.AddField(fc, "isUrban", "INTEGER")

Re: Updating a newly generated field with an update cursor

DanielFuller — Mon, 14 Jun 2021 14:39:53 GMT

you've saved my sanity Johannes I really appreciate it!

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Updating a newly generated field with an update cursor

Re: Updating a newly generated field with an update cursor

Re: Updating a newly generated field with an update cursor