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