Iterating through a Dictionary in Python (StopIteration Error)

Question

How do you iterate through a dictionary in python without the StopIteration Error? I created a list of events inside a dictionary that are assigned a time. I use a timer to check against that time and if the time of the event matches the timer, the event happens. This works fine until you reach the last event. Once you reach the last event in the dictionary, the event doesnt play and I get a StopIteration error because I have reached the end of the dictionary of events.

Prior to While loop

enemy_spawn_timer = pygame.time.get_ticks()
    event_dict = {"enemy1":3000, "enemy2":9000,"enemy3":5000, "END": 1000}
    next_event_key = next(iter(event_dict))

Inside of While loop

if pygame.time.get_ticks() > enemy_spawn_timer + event_dict[next_event_key]:
            enemy_spawn_timer = pygame.time.get_ticks()
            enemy = Enemy()
            enemy.rect.x = 518  # place offscreen
            enemy.rect.y = random.randrange(40, 184)  # account for the terrain
            enemy_list.add(enemy)
            del event_dict[next_event_key]
            next_event_key = next(iter(event_dict,))
            #if next_event_key == event_dict["END"]:
                #raise StopIteration

The last two lines were an attempt to stop the iteration without an error but didnt work.

Answer 1 · 2022-03-21T19:48:28Z

March 21, 2022 7:48pm

So you figured out that next() function returns the next item in an iterator. Nice work.

You can add a default return value in next() as the second parameter, to return if the iterable has reached its end.

Syntax

next(iterable, default)

I hope that helps.

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james wells

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Iterating through a Dictionary in Python (StopIteration Error)

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Jeff Muday

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