[python-committers] Providing .tgz sources

[Andrew Dalke]

On Dec 5, 2010, at 9:55 PM, Brett Cannon wrote:
> Well, is it more popular because that is just what people are used to
> downloading or the first download link on the web page? Or is it
> because people fundamentally prefer tgz files over tar.bz2?

I prefer tgz over tar.bz2 because my fingers are more used
to typing gz* than bz*, and because it's more likely that
gzip will be installed than bzip. But my habits were formed
before bzip was even available.

I have chosen bzip over gzip in cases where I know that
download bandwidth was limited but otherwise I use gzip.

Plus, Python comes with a gzip module. ;)

> Are there actual platforms that can't handle tar.bz2
> but can handle tgz?

I can test this tomorrow when I visit my client and type
"bzip" into a box there, but I think the answer is "yes."
This is a 3-4 year old Linux box where I had to install
a number of packages just to get it to state where I
could compile Emacs 23.x, since their package installer
doesn't have a new enough Emacs version.

Short version: most of the users log into the Linux
box to run pre-compiled chemistry applications. They
aren't doing development on the machines.

If Python was only available in bzip then I would have
to install bzip myself - which isn't hard - while I
grumble that it's more work for me for little savings.
After all, in these cases I'm at a large pharmaceutical
company with plenty of bandwidth, so the savings of a
few MB won't be noticeable.

They sure aren't going to have xz.

So, drop .tar.gz and I can still handle it.

> Personally I don't know why we have both tgz and tar.bz2 other than
> tradition. I say trim it down to tar.bz2 for portability and move on
> to using a ustar-based tar.xz to be cutting edge and minimize download
> size overall while making it the first download option to make sure
> people notice it.

While I would say to drop the bz2 and make it an xz instead.
*shrug* it's no big deal either which way.

If this is something you want to figure out, there's no
need for a poll. This is near ideal case for A/B testing.
Swap the two lines now and see what changes. And watch
the referrer logs to identify which downloads come
from that page.


Before today I had never even heard of .xz files. For
others who haven't heard of it, it's based on the LZMA2
algorithm, which is a slight improvement on the LZMA algorithm
which 7zip uses. It's been for about 2 years, and so I'm
surprised to see that it's part of the GNU coreutils already.

Here's a short read about the history
  http://linuxgazette.net/162/lindholm.html
with some numbers as well. It looks like the compression
time is a lot longer than gzip. This page
  http://stephane.lesimple.fr/wiki/blog/lzop_vs_compress_vs_gzip_vs_bzip2_vs_lzma_vs_lzma2-xz_benchmark_reloaded
recommends gzip if you want compression speed, and xz
if you want smaller size.


				Andrew
				dalke at dalkescientific.com