[Python-Dev] Garbage collecting closures (original) (raw)

Jeremy Hylton jeremy@alum.mit.edu
11 Apr 2003 23:38:14 -0400

On Fri, 2003-04-11 at 19:59, Paul Prescod wrote:

Does this bug look familiar to anyone?

No bug here.

import gc

def bar(a): def foo(): return None x = a foo() class C:pass a = C() for i in range(20): print len(gc.getreferrers(a)) x = bar(a) On my Python, it just counts up. "a" gets more and more referrers and they are "cell" objects. If it is unknown, I'll submit a bug report unless someone fixes it before I get to it. ;)

Nested recursive functions create circular references, which are only collected when the garbage collector runs. Add a gc.collect() call to the end of your loop and the number of referrers stays at 1.

Jeremy