[Python-Dev] Alternative path suggestion

[Gustavo Niemeyer]

> 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