[GIS] Split one field into 3 fields

arcgis-10.1arcpyattribute-tablefields-attributes

I need to split the values in a field according to what they represent to be able to do a join on the data. This is a cadastral polygon shapefile

As seen above I have a ID field that needs to be split into the following:

The ID consist of 21 digits where the first 8 digits represents the Town Code

The next 8 digits represents the ERF number

The last 5 digits represents the Portion number.

In there a way to easily split these into their own fields as I need to join a excel sheet to Town number, ERF and Portion.

For example:

C04100030000194800000

Will be split into their own fields:

TOWN: C0410003

ERF: 00001948

PORTION: 00000

I assume that this will be done with arcpy as I have over 50 000 records?

Best Answer

If the length of the ID field values is always constant I would recommend using either Field Calculator or Calculate Fields tool with python slices.

TOWN calculation:

!ID![:8]

ERF calculation

!ID![8:16]

PORTION calculation

!ID![-5:]

Related Solutions

[GIS] Field format lost when exporting events layer to shapefile – long field type converted to double

When adding table information from any source to arcmap, selecting the add xy option,
Arcmap programmatically converts the data (internally) to a spatial type and displays it on your map with the xy coordinates in the projection you choose.
When you select any data source and right click and choose export data there are no options to modify the output field type/s.
In order to accomplish this task so that you have EXACTLY the field type you want. Create an empty shapefile (utilizing steps 1-3 below).
Steps 1 and 2 keep you from having to manually add all your fields.
Import brings them in from your mdb.
This will provide a container with the correct field types in a shape file.
Then steps 4 and 5 will export the data with the wrong field types and you load that data into the container with the right field types.

Use these esri resources help pages to understand limitations and uses.
Data Type in the DBMS
ArcGIS Field Data Types

1.) create a new file geodatabase in arccatalog and on the field tab use the import feature.

new

import

2.) select the original file. (your accdb)
3.) modify the field type to exactly what you need.

modify

4.) export the data to a scratch shapefile. (or better yet file gdb.

5.) Load the data using simple loader to the file gdb you created with the specific fields.

loader

[GIS] Splitting strings into new rows, retaining geometry

you can use something like below :

import arcpy
searchC =  arcpy.da.SearchCursor(featureclass, ("type","code","area" , "SHAPE@")) #plus other attribute if you need

insertC = arcpy.da.InsertCursor(newfeatureclass, ("type","code","area" , "SHAPE@")) 

for row in searchC:
    A = [x.split(",") for x in row[:-1] ]

    for i in range(min(len(A[0]),len(A[1]),len(A[2]))):
        newRow = [A[0][i] , A[1][i], A[2][i], row[3]]
        insertC.insertRow(newRow)
del insertC

you can use a similar code to create a table instead of a feature class, as mentioned by Vince, so that you do not duplicate the geometries but instead create a one to many relation.

Best Answer

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[GIS] Field format lost when exporting events layer to shapefile – long field type converted to double

[GIS] Splitting strings into new rows, retaining geometry

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