[Talin] > 1) I don't know if this is already on the table, but I sure would like > to be able to have more options as far as mixing positional and > keyword arguments.
I thought it might be useful to look at a few places where we currently have to do some hackery to get the function signature we want. I believe the first of these can be solved by the proposed change. I'm not sure if anything can (or should) be done about the latter two. ------------------------------------------------------------------------ min/max (http://aspn.activestate.com/ASPN/Cookbook/Python/Recipe/389659) ------------------------------------------------------------------------ :: def __call__(self, *seq, **kwargs): key = kwargs.pop('key', None) if kwargs: raise TypeError("only 'key' accepted as a " "keyword argument") ... I believe this is straightforwardly cleaned up by the current proposal by making key a keyword only argument:: def __call__(self, *seq, key=None): ... ------------------------- UserDict.DictMixin.update ------------------------- :: def update(self, other=None, **kwargs): ... this is actually wrong, since you can't create a dict like ``dict(self='foo', other='bar')``. It needs to be written as:: def __init__(*args, **kwargs): if len(args) == 1: self, = args other = None else: self, other = args ... To clean this up, we'd need the ability to identify self and dict as positional only arguments. AFAICT, the current proposal doesn't solve this problem. Off the top of my head, I don't see an easy way of supporting this either... ---------------------- UserDict.DictMixin.pop ---------------------- :: def pop(self, key, *args): if len(args) > 1: raise TypeError, "pop expected at most 2 arguments, got "\ + repr(1 + len(args)) try: value = self[key] except KeyError: if args: return args[0] raise del self[key] return value Here, you *have* to know how many arguments were supplied because an exception must be raised if there were 2 and not if there were three. And even if you could define "default" as a keyword-only argument, e.g.:: def pop(self, key, *args, default=None): you still wouldn't know if "default" was None from the default in the signature or because the value None was supplied by the caller. STeVe -- Grammar am for people who can't think for myself. --- Bucky Katt, Get Fuzzy _______________________________________________ Python-3000 mailing list Python-3000@python.org http://mail.python.org/mailman/listinfo/python-3000 Unsubscribe: http://mail.python.org/mailman/options/python-3000/archive%40mail-archive.com
