[Python-Dev] ImportWarning flood

[Jean-Paul Calderone]

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