storage object behaves just like a Python dictionary but its contents
are preserved across game sessions. The values you assign to storage will be
saved as JSON, which means you can only store certain types of objects in it:
storage for a game is initially empty. Your code will need to handle
the case that values are loaded as well as the case that no values are found.
A tip is to use
setdefault(), which inserts a default if there is no value
for the key, but does nothing if there is.
For example, we could write:
After this line is executed,
storage['highscore'] will contain a value -
0 if there was no value loaded, or the loaded value otherwise. You could
add all of your
setdefault lines towards the top of your game, before
anything else looks at
storage.setdefault('level', 1) storage.setdefault('player_name', 'Anonymous') storage.setdefault('inventory', )
Now, during gameplay we can update some values:
if player.colliderect(mushroom): score += 5 if score > storage['highscore']: storage['highscore'] = score
You can read them back at any time:
def draw(): ... screen.draw.text('Highscore: ' + storage['highscore'], ...)
…and of course, they’ll be preserved when the game next launches.
These are some of the most useful methods of
storage[key] = value
Set a value in the storage.
Get a value from the storage. Raise KeyError if there is no such key in the storage.
Insert a default value into the storage, only if no value already exists for this key.
Get a value from the storage. If there is no such key, return default, or None if no default was given.
Remove all stored values. Use this if you get into a bad state.
Saves the data to disk now. You don’t usually need to call this, unless you’re planning on using
load()to reload a checkpoint, for example.
Reload the contents of the storage with data from the save file. This will replace any existing data in the storage.
The actual path to which the save data will be written.
As you make changes to your game,
storage could contain values that
don’t work with your current code. You can either check for this, or call
.clear() to remove all old values, or delete the save game file.
Remember to check that your game still works if the storage is empty!