[Import-SIG] PEP 420 issue: extend_path

[Eric V. Smith]

On 5/9/2012 12:14 PM, Barry Warsaw wrote:
> On May 09, 2012, at 06:19 PM, Nick Coghlan wrote:
> 
>> Eric's counter-proposal is to handle the 3 scenarios as:
>>
>> 1. (<loader>, <don't care>)
>> 2. (None, [<path entries>])
>> 3. (None, [])
> 

...

> I'd like to relax the formal specification just a bit though, so that the
> second element is a sequence, not necessarily a concrete list.

I was going to say just use whatever list.extend() is documented to
accept, but I notice that's "list" [1]. I would assume it can really be
any iterable. But since len() is called on it (in case 3, above), I
guess "sequence of strings" is the best description.

But if case 3 were changed to (None, None), then I wouldn't need to call
len(), and it could be any iterable returning strings in case 2. What
are your thoughts on making case 3 (None, None)? I sort of like it.

For case 1, I'm currently returning "<don't care>" part as an empty
string. Should I document it as that, or as really "<don't care>"? I
don't have an opinion on this.

Eric.

[1]: http://docs.python.org/tutorial/datastructures.html#more-on-lists