On Tue, Nov 20, 2012 at 6:41 PM, Barry Warsaw <barry@python.org> wrote:

On Nov 20, 2012, at 05:35 PM, Terry Reedy wrote:

>On 11/20/2012 3:35 PM, barry.warsaw wrote:
>
>> for entry in path:
>> + if not isinstance(entry, (str, bytes)):
>> + continue
>
>Given that a non-(str,bytes) entry could indicate a programming error, should
>a warning be emitted before continuing?

That's not what happens in Python 3.2.

Fine, but warnings are off by default and this is simply wrong behaviour to do. We should not paper over it just because import.c did.

In fact, this bug report was triggered
by someone who was already inserting None to sys.path[0]. It is silently
ignored in Python 3.2, but tracebacked in 3.3.

But why were they doing that? What did they hope to get out of it?