# -*- coding: utf-8 -*-
"""
Copyright Sylvain Bouveret, Yann Chevaleyre and François Durand
sylvain.bouveret@imag.fr, yann.chevaleyre@dauphine.fr, fradurand@gmail.com
This file is part of Whalrus.
Whalrus is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
Whalrus is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with Whalrus. If not, see <http://www.gnu.org/licenses/>.
"""
from whalrus.scales.scale_from_list import ScaleFromList
from whalrus.utils.utils import set_to_str
[docs]class ScaleFromSet(ScaleFromList):
# noinspection PyUnresolvedReferences
"""
Scale derived from a set.
Parameters
----------
levels : set
A set of comparable objects. It is recommended that they are also hashable.
Examples
--------
Typical usage:
>>> scale = ScaleFromSet({-1, 0, 2})
A more complex example:
>>> class Appreciation:
... VALUES = {'Excellent': 2, 'Good': 1, 'Medium': 0}
... def __init__(self, x):
... self.x = x
... def __repr__(self):
... return 'Appreciation(%r)' % self.x
... def __hash__(self):
... return hash(self.x)
... def __lt__(self, other):
... return Appreciation.VALUES[self.x] < Appreciation.VALUES[other.x]
>>> scale = ScaleFromSet({Appreciation('Excellent'), Appreciation('Good'),
... Appreciation('Medium')})
>>> scale.lt(Appreciation('Medium'), Appreciation('Good'))
True
>>> scale.low
Appreciation('Medium')
>>> scale.high
Appreciation('Excellent')
"""
def __init__(self, levels: set):
super().__init__(sorted(levels))
# noinspection PyMethodMayBeStatic
[docs] def lt(self, one: object, another: object) -> bool:
"""
Examples
--------
>>> scale = ScaleFromSet({-1, 0, 2})
>>> scale.lt(0, 2)
True
"""
return one < another
def __repr__(self):
"""
Examples
--------
>>> scale = ScaleFromSet({-1, 0, 2})
>>> repr(scale)
'ScaleFromSet(levels={-1, 0, 2})'
"""
return 'ScaleFromSet(levels=%s)' % set_to_str(set(self.levels))