[Python-Dev] Alternative path suggestion

Thu May 4 18:47:52 CEST 2006

> The biggest conceptual change is that my path object is a subclass of
> ''tuple'', not a subclass of str. For example,

Using tuples is a nice idea! Object paths using tuples is a somewhat
common concept. I don't see an immediate reason to be a *subclass*
of tuple, though, as opposed to using it as an internal representation.
> {{{
> p.normpath() -> Isn't needed - done by the constructor
> p.basename() -> p[-1]
> p.splitpath() -> (p[:-1], p[-1])
> p.splitunc() -> (p[0], p[1:]) (if isinstance(p[0], path.UNCRoot))
> p.splitall() -> Isn't needed
> p.parent -> p[:-1]
> p.name -> p[-1]
> p.drive -> p[0] (if isinstance(p[0], path.Drive))
> p.uncshare -> p[0] (if isinstance(p[0], path.UNCRoot))
>> and of course:
> p.join(q) [or anything like it] -> p + q
> }}}

Nice indeed.
> The only drawback I can see in using a logical representation is that
> giving a path object to functions which expect a path string won't
> work. The immediate solution is to simply use str(p) instead of p. The
> long-term solution is to make all related functions accept a path
> object.

Let's use __path_.. I mean, generic functions! ;-)
(...)
> * A ''relative path'' is a path without a root element, so it can be
> concatenated to other paths.
> * An ''absolute path'' is a path whose meaning doesn't change when
> the current working directory changes.

That sounds right.
> == Easier attributes for stat objects ==
>> The current path objects includes:
> * isdir, isfile, islink, and -
> * atime, mtime, ctime, size.
(...)
This indeed shouldn't be attributes of path, IMO, since they are
operations that depend on the state of the filesystem, and will
change behind your back.
> I think that isfile, isdir should be kept (along with lisfile,
> lisdir), since I think that doing what they do is quite common, and
> requires six lines:

I don't agree. "isdir" is an attribute of the filesystem, not of
the path object. I'd never expect that e.g. a network operation
could result from accessing an attribute in Python, and that could
certainly happen if the path is referencing a network filesystem.
-- 
Gustavo Niemeyer
http://niemeyer.net