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Python

Posted by Paxton Butler
Paxton Butler
6,338 Points

NoneType Error in Dungeon Game

I keep getting the following error every third or fourth time I run the dungeon game:

Traceback (most recent call last):
  File "dungeon.py", line 71, in <module>
    monster, door, player = get_locations()
TypeError: 'NoneType' object is not iterable

I think it is because something is wrong with how I call the get_locations() method in the if statement, but I can't figure it out!!

Here is my code:

def get_locations():
    monster = random.choice(CELLS)
    door = random.choice(CELLS)
    start = random.choice(CELLS)

    if monster == door or monster == start or start == door:
        get_locations()
    else:
        return monster, door, start
...
monster, door, player = get_locations()
move_history = []
move_history.append(player)

print("Welcome to the dungeon!")
print(monster)
print(door)
print(move_history)
Tobias Edwards
Tobias Edwards
14,458 Points

Can you post all your code, please?

1 Answer

Mikael Enarsson
Mikael Enarsson
7,056 Points
Mikael Enarsson
Mikael Enarsson
7,056 Points

It's a bit hard to tell, and the complete code would be more useful. However, there is one thing that stands out to me:

def get_locations():
    monster = random.choice(CELLS)
    door = random.choice(CELLS)
    start = random.choice(CELLS)

    if monster == door or monster == start or start == door:
        get_locations()        #Here, I'm fairly certain that you have to have
                               #return, in order to return the thing
                               #returned from the function to the
                               #thing that called the function
                               #in the first place.
    else:
        return monster, door, start

I could imagine that it's that, or maybe you haven't properly initialized CELLS?

Kenneth Love
Kenneth Love
Treehouse Guest Teacher
Kenneth Love
Kenneth Love
Treehouse Guest Teacher

My money, seeing just this snippet of code, would be that, yes, they need a return. Otherwise it just calls the function and nothing actually goes back to the code that wanted the values in the first place.