topic Re: ArcPro 3.1.2 - How to search and update fields in arcpy.da.UpdateCursor using field names and not index? in Python Questions

ArcPro 3.1.2 - How to search and update fields in arcpy.da.UpdateCursor using field names and not index?

VincentLaunstorfer — Tue, 12 Dec 2023 16:54:15 GMT

Hi,

In a Python script, I use arcpy.da.UpdateCursor but I need to read/write into rows using field names and not indexes, because fields to update are given as a parameter by the user.

When creating the update cursor, I select all fields '*' in order manipulate any fields.

However, it is a pain to read/update rows using indexes (dozens of fields)! I know rows are tuples but I really need to access fields using field names.

I spent time looking at documentation and posts but cannot find any proper syntax.

Help would be appreciated

Re: ArcPro 3.1.2 - How to search and update fields in arcpy.da.UpdateCursor using field names and not index?

AlfredBaldenweck — Tue, 12 Dec 2023 17:12:27 GMT

The row is a tuple, so you can use index(). Something along the lines of:

with arcpy.da.UpdateCursor(fc, "*") as cursor: for row in cursor: row[row.index("Field1")] = "Your value here" # etc. cursor.Update(row)

Re: ArcPro 3.1.2 - How to search and update fields in arcpy.da.UpdateCursor using field names and not index?

BlakeTerhune — Tue, 12 Dec 2023 17:20:52 GMT

I use this little function to iterate the rows as a dictionary instead of a tuple.

def rows_as_dicts(cursor): colnames = cursor.fields for row in cursor: yield dict(zip(colnames, row)) with arcpy.da.SearchCursor(r'c:\data\world.gdb\world_cities', '*') as sc: for row in rows_as_dicts(sc): print row['CITY_NAME']

Re: ArcPro 3.1.2 - How to search and update fields in arcpy.da.UpdateCursor using field names and not index?

Clubdebambos — Wed, 13 Dec 2023 10:14:55 GMT

There are a couple of very good answers here already to help you. If you are taking multiple field names in one parameter from a tool you can use the below to get them as a list of field names and then supply into your UpdateCursor.

## get multiple field names from user input in_flds = arcpy.GetParameterAsText(0) ## split into a list of field names in_flds = in_flds.replace("'", "").split(";") with arcpy.da.UpdateCursor(in_table, in_flds) as cursor: ...

You can also factor in either from @AlfredBaldenweck or @BlakeTerhune to achieve your updates.