@pablo: I am using Python 2.7.12 (distributed with Ubuntu 16), what are you using? This might explain the difference between what we see.

Yet, irrespective of this difference, imho, it would be a better design to have "close" actually closing the underlying resources.

In general, if one has to delete and/or invoke the garbage collector on an object, it's an indication that the design needs a bit of polish. Just picture the small scenario I described amplified to a situation where a large number of queues is used, which is perhaps an artificial scenario, but one would end up with a bunch of file descriptors hanging around for no reason.

This is what files and sockets, for example, would do.