made session dict usage a lot safer (using dict.setdefault("key, default) instead of directly using dict["key"])
from fabric.api import env
# the user to use for the remote commands
env.user = 'iri'
# the servers where the commands are executed
env.hosts = ['web.iri.centrepompidou.fr']
env.srv_venv_path = '/iridata/virtualenv/catedit'