Firstly, thanks to ChatGPT for helping with this - credit where credit is due!

The below python code will return a feature with an attribute new_code containing each of the missing codes between the specified start and end ones. In you python caller, make sure you expose new_code

import fme
import fmeobjects


class FeatureProcessor(object):

    def __init__(self):
        pass

    def has_support_for(self, support_type: int):
        return support_type == fmeobjects.FME_SUPPORT_FEATURE_TABLE_SHIM

    def increment_code(self, code):
        # Split the code into numeric and alphabetic parts
        numeric_part = int(code[:4])
        alpha_part = code[4:]

        # Convert alpha part to number
        alpha_number = (ord(alpha_part[0]) - ord('A')) * 26 + (ord(alpha_part[1]) - ord('A'))

        # Increment alpha number
        alpha_number += 1

        # If alpha number exceeds the range, reset and increment numeric part
        if alpha_number >= 26 * 26:
            alpha_number = 0
            numeric_part += 1

        # Convert back to code
        new_alpha_part = chr(alpha_number // 26 + ord('A')) + chr(alpha_number % 26 + ord('A'))
        return f"{numeric_part:04d}{new_alpha_part}"


    def input(self, feature: fmeobjects.FMEFeature):
        start = feature.getAttribute('postcode_van')
        end = feature.getAttribute('postcode_tot')

        curr = self.increment_code(start)

        while curr != end:
            feature.setAttribute('new_code', curr)
            self.pyoutput(feature)
            curr = self.increment_code(curr)

    def close(self):
        pass

    def process_group(self):
        pass

Having done similar in FME, then I’ve used Cloner for this.

Steps would be:

1. Convert the Postcode AlphaNumerics into Pure Numbers.   Effectively the form you have is that each “Number” is a Decimal Number 0-9 , or a Letter Number A-Z (26 Letter Numbers).   This 10+26 = A Base36 Number
2. Convert the PostCode Base36 “Numbers” into Decimal Numbers (Base10) using BaseConvertor
3. Use Cloner to create the extra intermediate features/rows based on the Difference between the Base10 postcode_tot_decimal number and the Base 10 postcode_vav_decimal number
4. Use AttributeCreator to set each new Feature/Row to a “postcode_sequence” number being postcode_van_decimal + the Cloner Sequence Number
5. Back convert the postcode_sequence Decimal Numbers (Base10) back to Base36 to get them back into Postcode Alphanumeric Format.
6. ListBuilder to wrap it into a List (Grouping into Lists effectively dissolves the Features into special List Attributes horizontally on the Feature)
7. Join the calculated Lists back into the Source Features with FeatureJoiner

*Edit*

Extra little Tester step to handle when an “Intermediate” Postcode has a 0-9 Number in either the 5th character or the 6th character, which is invalid.

 

Thanks for the options.

I tried both of them.

in my proces within FME option 1 worked well.

i just had to implement de postcode_van en postcode_tot.

The second one keeps running and gave me an out of memory.

thanks again.

kind regards

Laurens