Sentinel values for special cases
Ben Finney
bignose+hates-spam at benfinney.id.au
Fri Oct 27 20:06:13 EDT 2006
aahz at pythoncraft.com (Aahz) writes:
> Ben Finney <ben at benfinney.id.au> wrote:
> >Use a unique do-nothing object, defined at the module level so
> >callers can easily get at it [...]
> >
> > GLOBAL = object()
> >
> > def insert_ids(ids=GLOBAL):
> > if ids is GLOBAL:
> > ids = get_global_ids()
>
> The one disadvantage of this approach is that it complicates
> pickling if/when you store the stentinel in an instance. There are
> ways of working around that, but none are pleasant.
Hmm, and any other kind of serialisation would be similarly affected I
suppose.
What's an alternative?
--
\ "Think for yourselves and let others enjoy the privilege to do |
`\ so too." -- Voltaire, _Essay On Tolerance_ |
_o__) |
Ben Finney
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