Mike Frysinger wrote:
> unlike tinyurl, rafb.net expires.  please do not use links to rafb.net in 
> e-mails.
> -mike

Sorry, I normally paste to OSL (set to `forever'), dunno what went wrong
here... ebuild's attached.

# Copyright 1999-2007 Gentoo Foundation
# Distributed under the terms of the GNU General Public License v2
# $Header: $

NEED_PYTHON=2.4

inherit eutils distutils python multilib

DESCRIPTION="Python library for symbolic mathematics."
HOMEPAGE="http://code.google.com/p/sympy/"
SRC_URI="http://sympy.googlecode.com/files/${P}.tar.gz"

SLOT="0"

LICENSE="BSD"
KEYWORDS="~amd64 ~x86"
IUSE="examples math gtk latex plot test"

RDEPEND="math? (
		dev-libs/libxml2
		dev-libs/libxslt
		gtk? ( x11-libs/gtkmathview )
	)
	latex? (
		virtual/latex-base
		app-text/dvipng
		>=dev-python/pexpect-2.0
	)
	plot? (
		dev-python/pyopengl
		dev-python/imaging
		dev-python/ctypes
	)"
DEPEND="test? ( >=dev-python/py-0.9.0 )
	${RDEPEND}"

pkg_setup() {
	if use math ; then
		if ! built_with_use "dev-libs/libxml2" python ; then
			eerror "dev-libs/libxml2 has to be compiled with 'python' USE-flag."
			die "Needed USE-flag for dev-libs/libxml2 not found."
		fi

		if ! built_with_use "dev-libs/libxslt" python ; then
			eerror "dev-libs/libxslt has to be compiled with 'python' USE-flag."
			die "Needed USE-flag for dev-libs/libxslt not found."
		fi

		if use gtk && ! built_with_use "x11-libs/gtkmathview" gtk ; then
			eerror "x11-libs/gtkmathview has to be compiled with 'gtk' USE-flag."
			die "Needed USE-flag for x11-libs/gtkmathview not found."
		fi
	fi
}

src_test() {
	PYTHONPATH=build/lib/ "${python}" setup.py test || die "Unit tests failed!"
}

src_install() {
	distutils_src_install

	if use examples ; then
		insinto /usr/share/doc/${PF}
		doins -r examples
	fi

	python_version

	# 'pyglet' is not yet available in portage tree
	insinto ${ROOT}usr/$(get_libdir)/python${PYVER}/site-packages/sympy/thirdparty
	doins -r sympy/thirdparty/pyglet
}

pkg_postinst() {
	if ! has_version ">=dev-python/ipython-0.7.2" ; then
		elog
		elog "IPython 0.7.2 (or better) wasn't found on your system. It is"
		elog "highly recommended to install this package to optimize your"
		elog "work with SymPy. To do so, you can run:"
		elog
		elog " emerge '>=dev-python/ipython-0.7.2'"
		elog
	fi
}

pkg_postrm() {
	if use examples ; then
		python_mod_cleanup /usr/share/doc/${PF}
	fi
}