Fun side-effect of this: if you're writing a Python interpreter, you need to implement exceptions+"try...except" before you can fully implement the "for" loop.

Fun side-effect of this: if you're writing a Python interpreter, you need to implement exceptions+"try...except" before you can fully implement the "for" loop. And to implement this "except", you need classes and basic inheritance. EDIT: the second code in the article is slightly wrong. The for loop is actually equivalent to: iter_object = iter(my_list) while True: try: number = next(iter_object) except StopIteration: break sum += number # <-- the body of the original loop is here, outside the "try" print(sum) because if the body of the original "for" loop raises a "StopIteration", the loop doesn't catch it.