Why not lazily import modules by importing them when they are needed (i.e inside functions), and not in the top-level module scope?
On 10/13/05, Phillip J. Eby <[EMAIL PROTECTED]> wrote: > At 04:02 PM 10/13/2005 +0100, Michael Hudson wrote: > >Greg Ewing <[EMAIL PROTECTED]> writes: > > > > > Phillip J. Eby wrote: > > >> At 01:47 PM 10/13/2005 +1300, Greg Ewing wrote: > > >> > > >>> I'm trying to change the __class__ of a newly-imported > > >>> module to a subclass of types.ModuleType > > >> > > >> It happened in Python 2.3, actually. > > > > > > Is there a discussion anywhere about the reason this was > > > done? It would be useful if this capability could be > > > regained somehow without breaking things. > > > >Well, I think it's undesirable that you be able to do this to, e.g., > >strings. Modules are something of a greyer area, I guess. > > Actually, it's desirable to be *able* to do it for anything. But certainly > > for otherwise-immutable objects it can lead to aliasing issues. > > For mutable objects, it's *very* desirable, and I think the rules added in > 2.3 might have been overly strict, as they disallow you changing any > built-in type to a non built-in type, even if the allocator is the > same. It seems to me the safety check could perhaps be reduced to just > checking whether the old and new classes have the same tp_free. (Apart > from the layout and other inheritance-related checks, I mean.) > > (By the way, for an example use case other than modules, note that somebody > > wrote an "observables" package that could detect mutation of lists and > dictionaries in Python 2.2 using __class__ changes, which then became > useless as of Python 2.3.) > > _______________________________________________ > Python-Dev mailing list > Python-Dev@python.org > http://mail.python.org/mailman/listinfo/python-dev > Unsubscribe: > http://mail.python.org/mailman/options/python-dev/eyal.lotem%40gmail.com > _______________________________________________ Python-Dev mailing list Python-Dev@python.org http://mail.python.org/mailman/listinfo/python-dev Unsubscribe: http://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
