If your program needs to support many languages at the same time, you
may want to create multiple translation instances and then switch
between them explicitly, like so:
import gettext
lang1 = gettext.translation(languages=['en'])
lang2 = gettext.translation(languages=['fr'])
lang3 = gettext.translation(languages=['de'])
# start by using language1
lang1.install()
# ... time goes by, user selects language 2
lang2.install()
# ... more time goes by, user selects language 3
lang3.install()