[issue1820] Enhance Object/structseq.c to match namedtuple and tuple api

[Marc-Andre Lemburg]

Marc-Andre Lemburg <mal at egenix.com> added the comment:

Raymond Hettinger wrote:
> Raymond Hettinger <rhettinger at users.sourceforge.net> added the comment:
> 
> In Py3.x, this fails:
>     "%s.%s.%s-%s-%s" % sys.version_info
> 
> The reason is that PyUnicode_Format() expects a real tuple, not a tuple
> lookalike.  The fix is to either have structseq inherit from tuple or to
> modify PyUnicode_Format() to handle structseq:
> 
>    if (PyCheck_StructSeq(args)) {
>       newargs = PyTuple_FromSequence(args);
>       if (newargs == NULL)
>           return NULL;
>       result = PyUncode_Format(format, newargs);
>       Py_DECREF(newargs);
>       return result;
>    }

-1

The special-casing of tuples vs. non-tuples for % is already
bad enough. Adding structseq as another special case doesn't
make that any better.

What's so hard about writing

"%s.%s.%s-%s-%s" % tuple(sys.version_info)

anyway ?

----------
nosy: +lemburg
title: Enhance Object/structseq.c to match namedtuple and tuple api -> Enhance Object/structseq.c to match namedtuple and tuple	api

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<http://bugs.python.org/issue1820>
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