yeah, either something like that, or let RowProxy.__hash__ be hash(tuple(theRowProxy)) as IMO RowProxy has same meaning as tuple: readonly-row-ordered-in-constant-way
On Friday 09 January 2009 12:03:52 King Simon-NFHD78 wrote: > > -----Original Message----- > > From: sqlalchemy@googlegroups.com > > [mailto:sqlalch...@googlegroups.com] On Behalf Of > > a...@svilendobrev.com Sent: 08 January 2009 19:11 > > To: sqlalchemy@googlegroups.com > > Subject: [sqlalchemy] Re: SQLAlchemy 0.5 Released > > > > On Thursday 08 January 2009 21:03:42 Michael Bayer wrote: > > > On Jan 8, 2009, at 12:52 PM, a...@svilendobrev.com wrote: > > > > instead of None, better do some empty method raising some > > > > error, because in the current way the error comes up in not > > > > at all obvious fashion, takes quite some head-scratching to > > > > find-out - there's no mentioning of anything set() related > > > > there. > > > > > > __hash__ = None means no hash is defined. Its in the Python > > > docs. > > > > okay, have fun with > > TypeError: 'NoneType' object is not callable > > http://docs.python.org/reference/datamodel.html#object.__hash__ > implies that "__hash__ = None" only took on that special meaning in > Python 2.6 > > In Python 2.5, I think you're probably supposed to explicitly raise > a TypeError, but in Python 2.6 that would cause isinstance(obj, > collections.Hashable) to give the wrong answer. Maybe you could do > something like this: > > #------------------------------------------------------------------ >-- import sys > > if sys.version_info < (2, 6): > def unhashable(self): > raise TypeError('%s objects are not hashable' % > type(self).__name__) > else: > unhashable = None > > > def test(): > print "Testing on Python version %s" % (sys.version_info,) > class Dummy(object): > __hash__ = unhashable > > dummy = Dummy() > > try: > print "FAIL: hash(dummy) = %s" % hash(dummy) > except TypeError, e: > print "PASS: %s" % e > > if sys.version_info >= (2, 6): > import collections > if isinstance(dummy, collections.Hashable): > print "FAIL: isinstance(dummy, collections.Hashable) -> > True" > else: > print "PASS: isinstance(dummy, collections.Hashable) -> > False" > > if __name__ == '__main__': > test() > > #------------------------------------------------------------------ >-- > > That basic test seems to work on Python 2.4, 2.5 and 2.6. > > Simon > > --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "sqlalchemy" group. To post to this group, send email to sqlalchemy@googlegroups.com To unsubscribe from this group, send email to sqlalchemy+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sqlalchemy?hl=en -~----------~----~----~----~------~----~------~--~---
