[Python-Dev] ImportWarning flood (original) (raw)

Jean-Paul Calderone exarkun at divmod.com
Sat Jun 24 17:03:11 CEST 2006

On Sat, 24 Jun 2006 07:27:15 -0700, Aahz <aahz at pythoncraft.com> wrote:

On Sat, Jun 24, 2006, Jean-Paul Calderone wrote:

I am very unhappy that the burden of understanding Python's package structure is being pushed onto end users in this way. Several of my projects now emit three or four warnings on import now. The Twisted plugin system relies on the fact that directories without init are not Python packages (since they aren't, have never been, and it has always been extremely clear that Python will ignore them). Of course, Twisted is a pretty marginal Python user so I'm sure no one cares. Then again, bringing this back to the original source of this change, Google is a pretty marginal Python user, too. ;-)

I think it is safe to say that Twisted is more widely used than anything Google has yet released. Twisted also has a reasonably plausible technical reason to dislike this change. Google has a bunch of engineers who, apparently, cannot remember to create an empty init.py file in some directories sometimes.

I was a pretty strong -1 on the original proposed change of allowing import on empty directories, but my take is that if a project deliberately includes empty directories, they can add a new warning filter on program startup. Your users will have to upgrade to a new version of the application or do a similar fix in their own sitecustomize. I don't consider that a huge burden.

The usage here precludes fixing it in Twisted. Importing twisted itself prints a warning: there's no way to get code run soon enough to suppress this.

I do think requiring each user to modify sitecustomize is overly burdensome. Of course this is highly subjective and I don't expect anyone to come to an agreement over it, but it seems clear that it is at least a burden of some sort.

Jean-Paul

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