[SciPy-dev] Re: ASP: Ipython in SciPy

[Joe Harrington]

Ok, I see the problem if someone already has IPython and then installs
a SciPy RPM that includes IPython.  Perhaps that's not so crucial.  We
just need to make *sure* it's installed whenever a user runs scipy,
without fail.  This makes it "part of SciPy" to my way of thinking.
It's what we're documenting to, and what people will expect to see in
the future when they run scipy.

My concern is that a yum or apt command line with separate packages
will get long enough that people will mess it up.  It will be
something like

yum install scipy ipython matplotlib scipy-doc scipy-this scipy-that

This will inevitably lead to messed-up installs because some people
will always forget something, and omitting a package will not produce
any errors from yum.  The problem is solved by Enthon for Windows, and
the umbrella-package idea solves it for Linux.  If the recommended
installation command line is:

yum install scipy-all

That's much harder to mess up.  The umbrella package scipy-all would
install no files, or maybe a README, but would depend on scipy,
ipython, matplotlib, scipy-doc, scipy-this, and scipy-that in the
example above.  It would make sure those packages were there, but
would be happy if they were already there.  It would not install
anything twice.  So far nobody's argued against this idea.  Are there
any points against it?

Regarding docs, Ipython is not just a 2-paragraph thing.  Being the
outstanding doc writers that we are, we will offer examples on every
topic.  The prompt in those examples will be an Ipython prompt.  We'll
be telling users to use features of Ipython to debug and to get help,
among other things.  Use of these will come up repeatedly.  So if
Ipython isn't there, the prompts will look different, debugging will
be spooky, and the help won't work.  That's a recipe for disaster in
terms of user comfort and acceptance.  Certainly we need the 2
paragraphs, and maybe another about what you can expect if you run
*without* ipython.  But it doesn't stop there.  For example, we'll
want a section or chapter on how to debug a program, for people who
have never debugged before.

--jh--