What I have: I have 4 fields for my address ranges. L_ADD_FROM, R_ADD_FROM, L_ADD_TO & R_ADD_TO (all in DOUBLE field type).

What I need: The lesser value from L_ADD_FROM and R_ADD_FROM to populate in a field called FROMADDRESS.

I've searched extensively, trying Python and VB Script without much luck. What's the best method for this?

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  • What is your script you have written so far?
    – Hornbydd
    Mar 11, 2015 at 21:37
  • in Python use min([!FROM!,!TO!]) on destination field
    – FelixIP
    Mar 11, 2015 at 22:06

2 Answers 2


The following approach, using the Python parser, selects the min value from a list of input values.


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  • Wow, thanks a lot. That worked, there appears to be 800 ways to do this!
    – SpinTexas
    Mar 11, 2015 at 22:11
  • 1
    you could even get rid of a few lines and just have return min([x,y]) as your entire function definition. Get rid of the vals list altogether.
    – Fezter
    Mar 12, 2015 at 2:11
  • 2
    That's a really good outside-the-box way of doing it Aaron, +1 from me. As @Fezter indicated that would work if the only line was return min([x,y]) or even return min(x,y)... without the codeblock! (i.e. min(!L_ADD_FROM!, !R_ADD_FROM!) in this case even NULL can be considered - min(None,Value) returns None, if that's not acceptable then there would be a need for the codeblock (if not x == None..). Mar 12, 2015 at 2:29
  • Good call @Fezter and Michael Miles-Stimson. Post edited to address comments.
    – Aaron
    Mar 12, 2015 at 11:34

Right-click FROMADDRESS, as you want to populate that one, and open the Field Calculator.

  • Check the Python button
  • Check Show Codeblock

Now, in the bigger area you will insert this function:

def findSmallest(l_add, r_add):
    if l_add < r_add:
        return l_add
        return r_add

And in the smaller part below the "pre-logic script code" you will call that function, like this:

findSmallest(!L_ADD_FROM!, !R_ADD_FROM!)

This will iterate through each row in the table and put the value of R_ADD_FROM into l_add and the value of R_ADD_FROM into r_add, and then it will compare both. If l_add is smaller, it will write that one into FROMADDRESS (i.e. it will return it), and if it is not (i.e. if it is bigger), it will return the other value.

There is not right or wrong. You could surely do this with VB Script, but getting into Python is a smarter move as it is (becoming) the lingua franca of GIS scripting.

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