[ZODB-Dev] datetime types

[Marius Gedminas]

On Wed, Apr 30, 2003 at 04:08:51PM -0400, Tim Peters wrote:
> [Paolo Invernizzi]
> > The idatetime module was commited by 'ryzaja', but cannot I guess the
> > email address for asking if it's a known iussue...
> > I've read 'In prepration for the upcoming interface changes...' in the
> > latest interface/ log...
> >
> >> Python23 CVS
> >> ZODB CVS
> >> WinXP SP1
> 
> > [Viktorija Zaksiene]
> > It works with Python 2.2, but apparently not with Python 2.3. It
> > will be fixed when the new interface mechanism is checked in.
> 
> Python 2.3 implements the datetime module in C, and datetime.{datetime,
> date, time, timedelta, tzinfo} are implemented in C then.  Zope3 has a
> workalike datetime module coded in Python, so that the same interface can be
> used in Python 2.2.  datetime.{datetime, date, time, timedelta, tzinfo} are
> implemented in Python then.  You can generally add new attributes to classes
> implemented in Python, but generally not to classes implemented in C.

Yes.  With the current interface mechanism when you declare that a class
cls implements some interface, that information gets stored in
cls.__implements__.  As demonstrated above, this does not work for
built-in types, as demonstrated above.  However making it possible to
declare interfaces for built-in types is one of the explicitly stated
goals of the BetterInterfaceImplements proposal, thus this should get
fixed when that proposal is implemented.

Marius Gedminas
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