Using Python parser of ArcGIS Field Calculator to populate values in one field based on those in another?

Question

I am trying to populate a field with a sorting code that represents the value of another field. Example:

 EXPCODE|SORT|
 S4DNN2 |3.5
 H2BNN2  5.0

EXPCODE is a field with a value like "S4DNN2." SORT is a field that needs to represent the EXPCODE with a numerical value. What would I use for Python code to automatically populate the SORT field? I started with a simple "if" statement, but can't quite figure it out.

def EXPCODE(field_value):

    if field_value = "S4DNN2"
        return field_value "3.5"

    if field_value = "H2BNN2"
        return field_value "5.0"

The EXPCODE values I show are examples, I have about 67 different ones with unique numerical values that need to be populated in "SORT"

Any ideas?

Update: I am trying to execute this with the field calculator with use of the python parser

Answer 1

In your code:

def EXPCODE(field_value):

    if field_value = "S4DNN2"
        return field_value "3.5"

    if field_value = "H2BNN2"
        return field_value "5.0"

should probably be:

def EXPCODE(field_value):   
    if field_value == "S4DNN2":
        return 3.5  
    elif field_value == "H2BNN2":
        return 5.0

but if this is coming from the Field Calculator there may be more details that you need to provide before this will work for you.