[Python-Dev] Re: [Python-checkins] python/dist/src/Lib/test test_string.py, 1.25, 1.26

[Nick Coghlan]

Walter Dörwald wrote:
> I'm working on it, however I discovered that unicode.join()
> doesn't optimize this special case:

I noticed that during the implementation of the patch. I think it's 
because unicode join doesn't use a multi-pass approach, so there's no 
opportunity to notice that the optimisation is possible.

> s = "foo"
> assert "".join([s]) is s
> 
> u = u"foo"
> assert u"".join([s]) is s
> 
> The second assertion fails.
> 
> I'd say that this test (joining a one item sequence returns
> the item itself) should be removed because it tests an
> implementation detail.

Fine by me - I was uncertain about that when I posted the patch to SF 
(there's a question about it in the patch tracker item). The main reason 
I had that test there was to make sure that the second version of the 
patch didn't break this optimisation the way the first version did.

Regards,
Nick.