So by way of example - suppose I have this: # some other code if determined_value := some_function_call(): do_action(determined_value) and the

So by way of example - suppose I have this: # some other code if determined_value := some_function_call(): do_action(determined_value) and then I change it to this: # some other code determined_value = some_function_call() logger.info("Determined value was %s", determined_value) validate(determined_value) if determined_value: do_action(determined_value) and determined_value is a reasonably expensive operation (at the very least I would never want to redundantly do it twice) - then in this case my diff for this looks like: --- <unnamed> +++ <unnamed> @@ -1,5 +1,8 @@ - # some other code -if determined_value := some_function_call(): +determined_value = some_function_call() +logger.info("Determined value was %s", determined_value) +validate(determined_value) + +if determined_value: do_action(determined_value) whereas if I wrote it without walrus originally: --- <unnamed> +++ <unnamed> @@ -1,5 +1,8 @@ # some other code determined_value = some_function_call() +logger.info("Determined value was %s", determined_value) +validate(determined_value) + if determined_value: do_action(determined_value) then the diff is easier to read, and the intent is clearer because diff can simply infer that what's happening is the semantic addition of two lines. Code is read more then it's written, and changed more then originally created, and making the change case clearer makes sense.