75 lines
1.9 KiB
Python
75 lines
1.9 KiB
Python
"""
|
|
运算符重载 - 自定义分数类
|
|
|
|
Version: 0.1
|
|
Author: 骆昊
|
|
Date: 2018-03-12
|
|
"""
|
|
|
|
from math import gcd
|
|
|
|
|
|
class Rational(object):
|
|
|
|
def __init__(self, num, den=1):
|
|
if den == 0:
|
|
raise ValueError('分母不能为0')
|
|
self._num = num
|
|
self._den = den
|
|
self.normalize()
|
|
|
|
def simplify(self):
|
|
x = abs(self._num)
|
|
y = abs(self._den)
|
|
factor = gcd(x, y)
|
|
if factor > 1:
|
|
self._num //= factor
|
|
self._den //= factor
|
|
return self
|
|
|
|
def normalize(self):
|
|
if self._den < 0:
|
|
self._den = -self._den
|
|
self._num = -self._num
|
|
return self
|
|
|
|
def __add__(self, other):
|
|
new_num = self._num * other._den + other._num * self._den
|
|
new_den = self._den * other._den
|
|
return Rational(new_num, new_den).simplify().normalize()
|
|
|
|
def __sub__(self, other):
|
|
new_num = self._num * other._den - other._num * self._den
|
|
new_den = self._den * other._den
|
|
return Rational(new_num, new_den).simplify().normalize()
|
|
|
|
def __mul__(self, other):
|
|
new_num = self._num * other._num
|
|
new_den = self._den * other._den
|
|
return Rational(new_num, new_den).simplify().normalize()
|
|
|
|
def __truediv__(self, other):
|
|
new_num = self._num * other._den
|
|
new_den = self._den * other._num
|
|
return Rational(new_num, new_den).simplify().normalize()
|
|
|
|
def __str__(self):
|
|
if self._num == 0:
|
|
return '0'
|
|
elif self._den == 1:
|
|
return str(self._num)
|
|
else:
|
|
return '(%d/%d)' % (self._num, self._den)
|
|
|
|
|
|
if __name__ == '__main__':
|
|
r1 = Rational(2, 3)
|
|
print(r1)
|
|
r2 = Rational(6, -8)
|
|
print(r2)
|
|
print(r2.simplify())
|
|
print('%s + %s = %s' % (r1, r2, r1 + r2))
|
|
print('%s - %s = %s' % (r1, r2, r1 - r2))
|
|
print('%s * %s = %s' % (r1, r2, r1 * r2))
|
|
print('%s / %s = %s' % (r1, r2, r1 / r2))
|