Python Library Reference

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3.3.2 Example

This simple example shows how an application can use objects IDs to retrieve objects that it has seen before. The IDs of the objects can then be used in other data structures without forcing the objects to remain alive, but the objects can still be retrieved by ID if they do.

import weakref

_id2obj_dict = weakref.WeakValueDictionary()

def remember(obj):
    oid = id(obj)
    _id2obj_dict[oid] = obj
    return oid

def id2obj(oid):
    return _id2obj_dict[oid]

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Python Library Reference

Previous: 3.3.1 Weak Reference Objects Up: 3.3 weakref Next: 3.3.3 Weak References in

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Release 2.2, documentation updated on December 21, 2001.