Hafersack

Hafersack is a really small library to store and retrieve metadata in any object. Hafersack can store anything and uses strings as keys.

Installation

$ pip install hafersack  # or use your preferred package manager

How to use

Creating a singleton Hafersack instance is recommended, but not required. As long as you use the same key, you can access the same metadata from different Hafersack instances.

from hafersack import Hafersack

sack = Hafersack()

class MyClass:
    pass

obj = MyClass()

sack.set(obj, "key1", "value1")
sack.set(obj, "key2", 42)

assert sack.has(obj, "key1")
assert sack.has(obj, "key2")
assert not sack.has(obj, "key3")

assert sack.get(obj, "key1") == "value1"
assert sack.get(obj, "key2") == 42

sack.delete(obj, "key1")
assert not sack.has(obj, "key1")
assert sack.has(obj, "key2")