Keys

It is time to let players pick up keys. They should come in useful once we add some doors as well. To collect keys, we need to manage items in general. Again, a few steps are necessary:

1. add a key tile to the dungeon

2. add an items attribute to the game

3. pick up keys

4. draw all items in the inventory

Add a key tile

This works the same as for the earlier new tiles. Add a new character and image name to the SYMBOLS dictionary and add the new tile to the level.

Add an items attribute

To store items for later, the game needs an according data structure. For the inventory you need a data structure that can store multiple items. The inventory needs to have an order so that the inventory does not randomly rearrange itself.

A good data type for that situation is a Python list. Each item is going to be a string. Add a new field items to the DungeonGame class. At the beginning, the list of items should be empty:

items: list[str] = []

Pick up keys

To pick up a key you need to add it to the items list. Add an extra condition in the move_player() function that checks whether a new tile is a key. If it is, add a key to the list:

if game.level ... :
    game.items.append("key")

Also remove it from the map (same as with coins).

Draw the inventory

Drawing the items is similar to drawing a health bar from icons. However, you may want to collect many items later, so lets reserve more space. To draw items in multiple rows of 2 items each use the following loop in draw():

for i, item in enumerate(game.items):
    y = i // 2  # floor division: rounded down
    x = i % 2   # modulo: remainder of an integer division
    draw_tile(frame, xbase=660, ybase=96, x=x, y=y, image=images[item])

Hint

Multiple keys in an inventory could look like this:

If you like, you might create multiple keys as long as they have different symbols and names: b:blue_key, r:red_key etc.