In the early days of C, you’d occasionally see someone — probably a former Pascal programmer — write something like this: #define BEGIN { #define END } This would usually initiate… ...

For example, if you are building a game, then you might want the bulk of your code to continuously “loop” while you update the position of enemies and check for player inputs.

Any construct which deals with iterators will be prepared for this, like the for loop in our example. When this is run, it correctly stops at the appropriate point. $ python iterator_test.py 463 ...