On Mon, Jan 19, 2009 at 19:02, Scott Dial <scott+python-...@scottdial.com> wrote: > Brett Cannon wrote: >> 3. Are brackets for optional arguments (e.g. ``def fxn(a [, b=None [, >> c=None]])``) really necessary when default argument values are >> present? And do we really need to nest the brackets when it is obvious >> that having on optional argument means the rest are optional as well? > > I can't think of an example off the top of my head, but I'm certain the > point of nesting the brackets is to delimit the optional arguments into > groups. Documenting your fxn() examples as "fxn(a [, b=None, c=None])" > would imply that if you provide 'b' then you must provide 'c', or if we > abandon nested brackets, it's ambiguous as to the requirements. Imagine > seeing "foo(a [, b=None, c=None [, d=None]])" and I think the rationale > for such notation becomes clear.
Well, that is such a rare case that I don't know if it warrants the line noise in the argument declaration. That argument also doesn't make sense in the face of ``fxn(a [, a=None [, b=None]])`` where 'b' almost always has no connection to 'a', but is still supposed to be listed that way because of positional arguments being optional. I understand using them for C functions where there is no such thing as a default argument, but it just doesn't make a ton of sense for Python code. I don't know of anyone who was confused by what help() spit out and not having fancy bracketing. -Brett _______________________________________________ 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
