Python 3000: Standard API for archives?

[Chuck Rhode]

Tim Golden wrote this on Mon, 04 Jun 2007 15:55:30 +0100.  My reply is
below.

> Chuck Rhode wrote:

>> samwyse wrote this on Mon, 04 Jun 2007 12:02:03 +0000.  My reply is
>> below.

>>> I think it would be a good thing if a standardized interface
>>> existed, similar to PEP 247.  This would make it easier for one
>>> script to access multiple types of archives, such as RAR, 7-Zip,
>>> ISO, etc.

>> Gee, it would be great to be able to open an archive member for
>> update I/O.  This is kind of hard to do now.  If it were possible,
>> though, it would obscure the difference between file directories
>> and archives, which would be kind of neat.  Furthermore, you could
>> navigate archives of archives (zips of tars and other
>> abominations).

> Just put something together a module called "archive" or whatever,
> which exposes the kind of API you're thinking of, offering support
> across zip, bz2 and whatever else you want. Put it up on the
> Cheeseshop, announce it on c.l.py.ann and anywhere else which seems
> apt. See if it gains traction.  Take it from there.

> NB This has the advantage that you can start small, say with zip and
> bz2 support and maybe see if you get contributions for less common
> formats, even via 3rd party libs. If you were to try to get it into
> the stdlib it would need to be much more fully specified up front, I
> suspect.

Yeah, this is in the daydreaming stages.  I'd like to maintain
not-just-read-only libraries of geographic shapefiles, which are
available free from governmental agencies and which are riddled with
obvious errors.  Typically these are published in compressed archives
within which every subdirectory is likewise compressed (apparently for
no other purpose than a rather vain attempt at flattening the
directory structure, which must be reconstituted on the User's end
anyway).  Building a comprehensive index to what member name(s) the
different map layers (roads, political boundaries, watercourses) have
in various political districts of varying geographic resolutions is
much more than merely frustrating.  I've given it up.  However, I
believe that once I've located something usable, the thing to do is
save a grand unified reference locator (GURL) for it.  The GURL would
specify a directory path to the highest level archive followed by a
(potential cascade of) archive member name(s for enclosed archives) of
the data file(s) to be operated on.  Unpacking and repacking would be
behind the scenes.  Updates (via FTP) of non-local resources would be
transparent, too.  I think, though, that notes about the publication
date, publisher, resolution, area covered, and format of the map or
map layer ought to be kept out of the GURL.

My whole appetite for this sort of thing would vanish if access to the
shapefiles were more tractable to begin with.

-- 
.. Chuck Rhode, Sheboygan, WI, USA
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