On Wed, Feb 25, 2009 at 7:35 AM, Antoine Pitrou <solipsis@pitrou.net> wrote:
I would like to know if both IO implementations (the C one and the Python one) should share their ABCs (IOBase, RawIOBase, etc.). It looks preferable to me but since I'm not very familiar with ABCs I'd like to be sure it's the good choice.
(of course, the *implementations* won't be shared at all. Just the virtual inheritance information)
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). Another way to solve it would be to use the registration API for ABCs, as found in _abcoll.py (e.g. MutableSequence.register(list)). -- --Guido van Rossum (home page: http://www.python.org/~guido/)