I'm making a model builder to automatize some linear referencing projects but I have some problems with the field calculator tool.

My table contains 3 fields : ID | NOM | LIGNE and I'd like to complete the "LIGNE" field.

This row is numeric and it is composed by the 6 first number of the ID number 1.

I made a little picture to illustrate my problem :

(source: canardpc.com)

To resume, I'd like to complete my "LIGNE" field with the code "456789" which is the code line of the first ID.

Please... Could you help me ??

  • 2
    Please accept the answer that solved your problem. To mark an answer as accepted, click on the check mark beside the answer to toggle it from hollow to green
    – BERA
    Oct 10, 2016 at 17:12

3 Answers 3


Use the field calculator, select your field 'ligne' and try:

Split( [NOM] , " ")(0)

It splits the field (in your case "NOM") by whitespace characters (" ") and returns the first (index 0) segment.
This is a string operation, so the resulting data type is also a string. In case your result field has another type (e.g. integer), you have to convert it, like

CInt(Split( [input_field] , " ")(0))

If the input value can be empty, you have to check first by using VBScript (in Pre-Logic Script Code), e.g.

value =  Split( [input_field] , " ")
If ubound(value) >= 0 Then
  result = value(0)
  result = ""
End if

and assign "result" to your field

  • Hello ! Thank you for your help but it dosen't work. The result is good juste for the first ID and the others are "NULL". I have the same result when I made "left([NOM],6)". What I want to do is to input the first value of the "NOM" field to the others.
    – bp03
    Oct 10, 2016 at 11:43
  • @bp03: see the updated script, you have to put it in the "Pre-Logic Script Code" field, thanks to @fatih_dur!
    – Greg Z
    Oct 10, 2016 at 12:21

Instead of Field Calculator you can use a python script and updatecursor. A python script can be can be integrated into models or executed inside ArcMap using the python window.

import arcpy
table = r'C:\TEST.gdb\Table123'
with arcpy.da.UpdateCursor(table,['NOM','LIGNE']) as ucurs:
    for row in ucurs:
        except ValueError:

enter image description here


Try this (with an evident inspiration from @Greg Z) after setting your parser to Python and selecting Show Codeblock (inside Pre-Logic Script Code):


def ligne_process(val):
    global nom
    val=long(val) if val.strip().isdigit() else False        
    if val and nom!=val:            
    return nom

And paste the following code in the smaller box below the Pre-Logic Script Code


This code assumes, as @Greg Z highlighted, your target integer ID in NOM field is the first part just before the first colon (:) and your LIGNE field is an integer/numeric type.


I have edited my answer as to respond your linear referencing related enquiry.

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