##
## Simple example:
from preferences import Preferences
prefs_defaults = {"X": 1, "Y": 2}
prefs = Preferences(defaults=prefs_defaults, filename="preferences_test.txt")
# At first use, attributes are initialized to default
# If previous uses set them at different values, the default value will
# not override the 'different value'.
assert prefs.X == 1 and prefs.Y == 2 # True
# By setting the following attributes, their new values are
# automatically stored into the file.
prefs.X = 3
prefs.Y = 4
# attributes can be defined without default values.
prefs.Z = 5
# RESTART program (re-initializing 'prefs' gives the same results as
# restarting. Since defaults are stored, you are not
# required to give them default values again.
# However, when restarting the script, this is
# usually unavoidable. )
prefs = Preferences(defaults=prefs_defaults, filename="preferences_test.txt")
# Old values have been remembered.
assert prefs.X == 3 and prefs.Y == 4 and prefs.Z == 5 # True
