Use case 2: Python and other interpreted languages

$ spack install python@2.7.10
==> Building python.
==> Successfully installed python.
  Fetch: 5.01s. Build: 97.16s. Total: 103.17s.
[+] /srv/jupyterhub/spack/opt/spack/linux-x86_64/gcc-4.9.2/python-2.7.10-y2zr767
$ spack extensions python@2.7.10
==> python@2.7.10%gcc@4.9.2=linux-x86_64-y2zr767
==> 49 extensions:
geos            py-h5py         py-numpy        py-pypar            py-setuptools
libxml2         py-ipython      py-pandas       py-pyparsing        py-shiboken
py-basemap      py-libxml2      py-pexpect      py-pyqt             py-sip
py-biopython    py-lockfile     py-pil          py-pyside           py-six
py-cffi         py-mako         py-pmw          py-python-daemon    py-sphinx
py-cython       py-matplotlib   py-pychecker    py-pytz             py-sympy
py-dateutil     py-mock         py-pycparser    py-rpy2             py-virtualenv
py-epydoc       py-mpi4py       py-pyelftools   py-scientificpython py-yapf
py-genders      py-mx           py-pygments     py-scikit-learn     thrift
py-gnuplot      py-nose         py-pylint       py-scipy
==> 3 installed:
-- linux-x86_64 / gcc@4.9.2 ------------------------------------
py-nose@1.3.6   py-numpy@1.9.2  py-setuptools@18.1
==> None currently activated.

$ spack activate py-numpy
==> Activated extension py-setuptools-18.1-gcc-4.9.2-ru7w3lx
==> Activated extension py-nose-1.3.6-gcc-4.9.2-vudjpwc
==> Activated extension py-numpy-1.9.2-gcc@4.9.2-45hjazt

$ spack deactivate -a py-numpy
==> Deactivated extension py-numpy-1.9.2-gcc@4.9.2-45hjazt
==> Deactivated extension py-nose-1.3.6-gcc-4.9.2-vudjpwc
==> Deactivated extension py-setuptools-18.1-gcc-4.9.2-ru7w3lx