[Python-Dev] frozenset C API? (original) (raw)

Bill Janssen janssen at parc.com
Tue Sep 4 21:21:37 CEST 2007

I'm working on issue 1583946. Nagle pointed out that each DN (the "subject" and "issuer" fields in a certificate) may have multiple values for the same attribute name, and I haven't been able to rule this out yet. X.509 DNs are sets of X.500 attributes, and X.500 attributes may be either single-valued or multiple-valued. I haven't found anything in the X.509 standard that prohibits multiple-valued attributes (yet -- I'm still looking), so I'm working on an alternative to using dicts to represent the set of attributes in the certificate that's returned from ssl.sslsocket.getpeercert(). "frozenset" seems the most appropriate -- it's a non-ordered immutable set of attributes. Could use a tuple, but (1) that implies order, and (2) using set operations on the attribute set would be handy to test for various things, particularly "issubset" and "issuperset".

I think frozenset is quite analogous to tuple at this level, and I suggest that a similar set of C construction functions would be a good thing.

Bill

I guess nobody has tried to create frozenset instances from C code before. Almost everyone uses set anyway. What are you trying to do?

On 9/4/07, Bill Janssen <janssen at parc.com> wrote: > I'm looking at building a "frozenset" instance as a return value from > a C function, and the C API seems ridiculously clumsy. Maybe I'm > misunderstanding it. Apparently, I need to create a list object, then > pass that to PyFrozenSetNew(), then decref the list object. > > Is that correct? > > What I'd like is something more like > > PyFrozenSetNEW(int) => PySetObject * > PyFrozenSetSETITEM(s, i, v) > > Any idea why these aren't part of the API? > > Bill _> ________________________ > Python-Dev mailing list > Python-Dev at python.org > http://mail.python.org/mailman/listinfo/python-dev > Unsubscribe: http://mail.python.org/mailman/options/python-dev/guido%40python.org >

-- --Guido van Rossum (home page: http://www.python.org/~guido/)

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