breaking iteration of generator method

[Tim Hochberg]

Brian wrote:
> Hello;
> 
> What happens when a program breaks (think keyword 'break') its iteration
> of a generator? Is the old state in the generator preserved?
> 
> Ex:
> 
> # .gen() is generator method.
> 
> for i in myObject.gen():
> 	if i == specialValue:
> 		break
> 
> Do subsequent calls to .gen() start off with new locals?

It depends on how you do it. This::


  for i in myObject.gen():
  	if i == specialValue:
  		break
         # ...
  for i in myObject.gen():
  	if i == otherSpecialValue:
  		break
         # ...

Will start start with a new generator with new local each time since 
each call to gen() creates a fresh generator. If you want to preserve 
generator state between loop, what you do is::

   generator = myObject.gen()
   for i in generator:
  	if i == specialValue:
  		break
         # ...
   for i in generator:
  	if i == otherSpecialValue:
  		break
         # ...

In this case, the same generator is used in each loop and the state is 
preserved.

-tim



> Or, would
> the iteration begin after the yielded 'i' that caused the for-statement
> to exit?
> 
> 
> Many thanks,
> 
> Brian.