First python extension package: setuptools

var/spack/packages/py-setuptools/package.py

+from spack import *
+
+class PySetuptools(Package):
+    """Easily download, build, install, upgrade, and uninstall Python packages."""
+    homepage = "https://pypi.python.org/pypi/setuptools"
+    url      = "https://pypi.python.org/packages/source/s/setuptools/setuptools-11.3.tar.gz"
+
+    version('11.3.1', '01f69212e019a2420c1693fb43593930')
+
+    extends('python')
+
+    def install(self, spec, prefix):
+        site_packages_dir = "%s/lib/python2.7/site-packages" % prefix
+        mkdirp(site_packages_dir)
+
+        env['PYTHONPATH'] = site_packages_dir
+
+        python = which('python')
+        python('setup.py', 'install', '--prefix=%s' % prefix)