A dummy in-memory cache for development and testing. (Not recommended for production use.)
>>> pip install dummycache
>>> from dummycache import Cache >>> c = Cache()
The basic interface is set(key, value, timeout=None) and get(key, default=None):
>>> c.set('key_a', 'Good morning, today!', 60) # Set value in cache for 60 seconds >>> c.get('key_a') 'Good morning, today!'
Wait 60 seconds:
>>> c.get('key_a') None
If timeout is not provided, the value is saved forever or until it is overridden or explicitly deleted:
>>> c.set('key_b', 'Good afternoon, forever!') # Set value in cache forever
If timeout is zero or negative, the value is not saved. The value previously saved with the same key will also be deleted:
>>> c.set('key_b', 'Good bye', 0) # The value is not set >>> c.get('key_b') None
cache.get() can take a default argument. This specifies which value to return if the object doesn’t exist in the cache:
>>> c.get('key_a', 'has expired') 'has expired'
To add a key only if it doesn’t already exist, use the add() method. It takes the same parameters as set(), but it will not attempt to update the cache if the key specified is already present:
>>> c.set('key_c', 'Initial value') >>> c.add('key_c', 'New value') >>> c.get('key_c') 'Initial value'
If you need to know whether add() stored a value in the cache, you can check the return value. It will return True if the value was stored, False otherwise.
You can delete keys explicitly with delete(). This is an easy way of clearing the cache for a particular object:
- Finally, if you want to delete all the keys in the cache, use clear(). Be careful with this; clear() will remove
- everything from the cache, not just the keys set by your application.