On Wed, Feb 25, 2009 at 1:31 PM, Nick Coghlan <ncogh...@gmail.com> wrote: > Guido van Rossum wrote: >> On Wed, Feb 25, 2009 at 1:03 PM, Antoine Pitrou <solip...@pitrou.net> wrote: >>> Guido van Rossum <guido <at> python.org> writes: >>>> Without a shared ABC you'd defeat the whole point of having ABCs. >>>> >>>> However, importing ABCs (which are defined in Python) from C code >>>> (especially such fundamental C code as the I/O library) is really >>>> subtle and best avoided. >>>> >>>> In io.py I solved this by having a Python class inherit from both the >>>> ABC (RawIOBase) and the implementation (_fileio._FileIO). >>> My plan (let's call it "the Operation") is to define the ABCs in Python by >>> deriving the C concrete base classes (that is, have io.XXXIOBase derive >>> _io.XXXIOBase). This way, by inheriting io.XXXIOBase, user code will benefit >>> both from ABC inheritance and fast C concrete implementations. >> >> However that's hardly an ABC. You need to provide a path for someone >> who wants to implement the ABC without inheriting your implementation. > > Don't they already have that through register()?
I'd like the ABCs to remain just as abstract or concrete as they are in 3.0. As long as the C version implements the same methods with the same semantics as the 3.0 io.py I don't care. > However, the other problem with setting up the inheritance as Antoine > suggests is that it makes it impossible to import a pure Python version > of the module. Once the Python code inherits from something provided > only by the C module then the C version isn't optional any more. I think this should be taken care of by having separate _pyio.py and _cio.py modules which are unified by io.py, right? (Or whatever naming convention is agreed upon; I skipped that thread. :-) -- --Guido van Rossum (home page: http://www.python.org/~guido/) _______________________________________________ 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
