Why my IF statement and OR operator doesn't give me the expected output?

I'm actually not sure what is wrong here, but the code just doesn't give me what I want.

Technically, what I want it to do is if I write '0' which will be in the dictionary (can be more depending how many items it has) or 'N', it will stop. But it doesn't work. It always run the if instead of the else.

Is it something obvious that I can't see or just a bug (unlikely)

from time import sleep

inventory = {}
character = {'Energy': 180}
inventory['Red Mushroom'] = {'Quantity': 1,
                                   'Description': 'It looks good for the Energy, but also a tasteful snack...',
                                   'Effect': 35}

def show_inve():
    sleep(1)
    mapear = {}
    if inventory == {}:
        print('Its empty...\n')
    else:
        for i, pos in enumerate(inventory):
            print(f'[{i}] {pos:<10}: {inventory[pos]["Quantity"]:>0}')
            mapear[str(i)] = pos

        while True:
            sleep(1)
            decision = input('Type the number of the item or N to leave: ').strip()
            if decision not in mapear or decision != 'N':
                sleep(1)
                print('Not an option.')
                continue
            else:
                break


show_inve()