Python script to field calculate one field based on another field's value

[SusanO_Connell]

I would like to find a python script to field calculate one field based on another field's value.  For example, "Field B" will have a code '23' if "Field A" is equal to CST, or if it is equal to AFF, it will be '11'. Also need to know what to use as a wildcard if CST or AFF is followed by more descriptions.

[MahtabAlam1 · Accepted solution]

It will require a code block which is nothing but a python function. Please refer Calculate Field Examples

So all you need is something like

def cal( valA):

    if(valA.startswith('CST') or valA.startswith('AFF')):

        return 11

    else:

        return

and call it as

cal(!Field_A!)

Hope that helps.

[SusanO_Connell]

Thank you very much!

Susan O’Connell

Geographic Information Systems

GIS Specialist

[XanderBakker]

Hi Susan O'Connell‌,

If your the solution provided by Mahtab Alam‌ solved your problem (and I think it did), could you please mark his answer as the correct one.

Thank you,

Xander

GeoNet Moderator

[XanderBakker]

Hi Susan O'Connell,

I think you ment to mark the answer by Mahtab Alam as helpful, right? Since you marked your own response as helpful.