[AstroPy] Deployment and packaging

[Andrew Williams]

On 15/06/2011 10:43 AM, Tommy Grav wrote:
>
> On Jun 14, 2011, at 10:11 PM, Perry Greenfield wrote:
>> IRAF is only one example. SExtractor is another. And there are
>> others. There isn't yet enough to replace these, and won't be for
>> some years (if ever, it is probably silly to think everything we
>> need will be in Python, or that there won't be some very useful
>> things out there not written in Python).
>
> My opinion is that those tools belong in as separate packages. To me
> they just don't

I strongly agree - people who work with tools like these already will be 
_less_ likely to adopt an 'astropy' package if it also includes an extra 
copy of SExtractor, IRAF, and every other tool they might possibly want, 
generating conflicts with anything that's already installed.

'All in one' setups like this make life easier for people setting up new 
computers for training workshops or for new postgrads, but they make 
life a lot harder for people who already have the tools they need set 
up, and don't want to break them by installing some monolithic 
collection of loosely coupled packages. It's that latter set of expert 
users who are the ones you most want to get involved using and 
contributing to the collection...

For the same reason, I'm also very much against the idea of turning this 
into another complete python distribution. Apart from Windows users, 
most people already have Python installed with the operating system. 
Installing a second copy (and getting all the other libraries you want 
to use installed under _both_ Python versions) is a real pain.

There's nothing to stop people re-packaging 'astropy', or whatever the 
Python-only collection gets called, along with SExtractor, IRAF, numpy, 
and everything else, if there is demand for an 'all in one' collection.

I'm more used to catering for the other end of the user base - the 
people who, at worst, _only_ have access to software that's part of the 
default OS install, or at best, packages maintained in the ubuntu/fedora 
software systems. For example, I wrote a pyfits-like FITS file library 
in pure Python for people who couldn't get pyfits installed on the 
machine they had to use...

Another point - if this 'astropy' collection is maintained as a 
ubuntu/fedora package (plus the OSX equivalent, I forget the name), it 
will expand the available user base hugely - an awful lot of people use 
computers they don't have root access for. It's really, really hard to 
convince most sysadmins to download some random piece of software off 
the internet and install it on a machine unless it's maintained in the 
software packaging system for that OS.

The more things you add, like SExtractor and numpy (which are both 
already distinct ubuntu packages), the harder it will be to package it 
properly that way.

Andrew