Mapytex/mapytex/calculus/core/MO/fraction.py

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#! /usr/bin/env python
# -*- coding: utf-8 -*-
# vim:fenc=utf-8
#
# Copyright © 2017 lafrite <lafrite@Poivre>
#
# Distributed under terms of the MIT license.
from mapytex.calculus.core.tree import Tree
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from .mo import MO
__all__ = ["MOFraction"]
class MOFraction(MO):
""" Fraction math object"""
def __init__(self, numerator, denominator, negative=False):
""" Initiate the MOFraction
It can't be indempotent.
:param numerator: Numerator of the Fraction
:param denominator: Denominator of the Fraction
:param negative: Is the fraction negative (not concidering sign of
numerator or denominator.
>>> f = MOFraction(2, 3)
>>> f
<MOFraction 2 / 3>
>>> f = MOFraction(2, 3, negative = True)
>>> f
<MOFraction - 2 / 3>
"""
base_value = Tree("/",
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MO.factory(numerator),
MO.factory(denominator),
)
if negative:
value = Tree("-", None, base_value)
else:
value = base_value
MO.__init__(self, value)
self._numerator = numerator
self._denominator = denominator
self.negative = negative
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@property
def numerator(self):
""" Get the numerator. If self is negative, getting the opposite of the _numerator
"""
if self.negative:
return Tree("-", None, self._numerator)
return self._numerator
@property
def denominator(self):
return self._denominator
def inverse(self):
""" return the inverse fraction """
return MOFraction(self._denominator,
self._numerator,
self.negative)
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