> ...Especially if there is a very common refactoring bug and you get a pepperoni pizza instead of a pizza with one of the most natural toppings like pineapple.

> ...Especially if there is a very common refactoring bug and you get a pepperoni pizza instead of a pizza with one of the most natural toppings like pineapple. Exactly! The DRY'ed example in the first section should read rather: def make_hawaiian_pizza(): make_pizza(["ham","pineapple"]) This demonstrates the omnipresent dangers of untested copy-paste. "Copy-paste, copy-paste, Will Robinson!!"