Interesting, had not considered that at all.
So basically, to ensure the old reference is not released, just naming it would do the trick? AKA:<p><pre><code>    &gt;&gt;&gt; some_unbound_method = A.b
    &gt;&gt;&gt; hex(id(some_unbound_method))
    &#x27;0x104e2c0a0&#x27;</code></pre>