Weak references in Python allow you to reference objects without preventing garbage collection, solving memory leak issues in cyclic data structures, caches, and subscriber lists. The weakref module provides tools like WeakValueDictionary and WeakSet for automatic cleanup, plus callback mechanisms for custom finalization logic. These features help build memory-efficient systems that respect object lifetimes while avoiding manual cleanup overhead.
Table of contents
A Review of Reference CountingHow CPython Implements Reference Counting: Dissecting CPython InternalsLimitations of Reference CountingCPython Garbage Collection: The Internal Mechanics and AlgorithmsUnderstanding Weak ReferencesOther Use Cases of Weak ReferencesConclusionFurther Reading1.4K Impressions