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<H2><A NAME="SECTION005320000000000000000"></A><A NAME="weakref-example"></A>
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3.3.2 Example
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<P>
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.

<P>
<div class="verbatim"><pre>
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]
</pre></div>

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<span class="release-info">Release 2.4.2, documentation updated on 28 September 2005.</span>
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