Question

Is there a way to prevent StopIteration exceptions from being thrown from unrelated code (without having to catch them manually)?

Example: loop_all wants to loop through the myiter iterator and simply move on when this one has finished. This works unless some_dangerous_method or any other code in myiter raises a StopIteration.

def loop_all():
    myiter = myiter()
    try:
        while True:
            next(myiter) # <- I want exactly the StopIteration from this next method
    except StopIteration:
        pass

def myiter():
    some_dangerous_method() # what if this also raises a StopIteration?
    for i in some_other_iter():
        # here may be more code
        yield

Is there a way to make it clear to which StopIteration the code should react to?

Answer 1

If a function you are calling is invoking next(iter), and isn’t dealing with StopIteration, then that function has a bug. Fix it.