支持四则运算的分数类

Fraction.py

##! %Python_Home%/python3
#-*- coding:utf-8 -*-
#@Time: 2020-07-01
#@Author: LiuQixuan
#@Email: [email protected]
#@File: Fraction.py
#@Description: 	Fraction 类为一个支持四则运算的分数类,构造函数接受可变长参数.表示为"分子/分母",仅支持真分
#		数假分数表示,不支持带分数表示.
#		参数说明:构造函数可接受单个字符型参数或多个整数浮点字符混合参数,但是最终处理参数不多于一个.无参数时
#		返回自然数1的分数形式.构造参数一般形态{4/5},接受浮点型{5/1.2},{3.4/1.3},	{2.7/3}等出现浮点型时自动
#		转化为"分子/分母"表示形式.构造函数接受字符型{"1.2/5"},{"2/7"},{"1.2"},{"3"},最终,全部转化
#		为"分子/分母"形式.
#		特殊情况:{0}或{"0"},结果为0/1.{number/0}结果是nan / nan并抛出分母不能为零异常.
#		静态函数:类提供一般的获取分子(numerator),分母(denominator)的接口,可直接修改就像使用一般静态变量一
#		样,实际上是用装饰器实现的,例如:frac.denominator = 123,print(frac.denominator).类还提
#		供getSimplifyFrac方法用于处理认为赋值导致结果未统分的分数.
#		输出方式:可直接使用print(frac)进行输出,也可以使用类自带的输出方法输出frac.print()使用toFloat方法返
#		回Float类型的分数浮点值.
#		说明:最终结果皆是统分后的最简结果.
#				
from math import floor

class Fraction():
	def __init__(self,*args):
		# print('[Info] Args:',args)
		# print('[Info] Args.length:',len(args))
		numerator,denominator = [1,1]
		if(args == ()):
			numerator,denominator = [1,1]

		elif(isinstance(args[0],str)):
			numerator,denominator = self.__byString(args[0])
		elif(len(args)==1):
			if(isinstance(args[0],int)):
				numerator,denominator = [args[0],1]
			elif(isinstance(args[0],float)):
				numerator,denominator = self.__byFloat(args[0])
		else:
			if(args[1] == 0 or args[1]=='0'):
				try:
					raise Exception('[ERRO] Exception: parameter error: the denominator cannot be zero')
				except Exception as e:
					print(e.args[0])
				finally:
					numerator,denominator = [float('nan'),float('nan')]
			elif(args[0] == 0):
				numerator,denominator = [0,1]
			elif(isinstance(args[0],int) and isinstance(args[1],int)):
				numerator,denominator = [args[0],args[1]]
			else:
				frac = Fraction(args[0])/Fraction(args[1])
				numerator,denominator = [frac.numerator,frac.denominator]
		
		self._numerator = numerator
		self._denominator = denominator
		# print(f'[Success] Fraction: build success.',f"{self._numerator}/{self._denominator}")
	
	@property
	def numerator(self):
		return self._numerator

	@property
	def denominator(self):
		return self._denominator
	
	@numerator.setter
	def numerator(self,v):
		self._numerator = v

	@denominator.setter
	def denominator(self,v):
		self._denominator = v


	def __byString(self,str):
		numerator,denominator = [1,1]
		if(str.find('/')==-1):
			numerator,denominator = self.__byFloat(float(str))
		else:
			argArr = str.split('/',1)
			if (argArr[1] == '0'):
				try:
					raise Exception('[ERRO] Exception: parameter error: the denominator cannot be zero')
				except Exception as e:
					print(e.args[0])
				finally:
					numerator,denominator = [float('nan'),float('nan')]
			else:
				frac = Fraction(argArr[0])/Fraction(argArr[1])
				numerator,denominator = [frac.numerator,frac.denominator]
		return [numerator,denominator]
	
	def __byFloat(self,v_f):
		lenOfDeno = len(str(v_f).split('.')[1])
		denominator = lenOfDeno*10
		numerator = v_f*denominator
		numerator,denominator = self.__simplifyFrac(numerator,denominator)
		return [numerator,denominator]
	
	@staticmethod
	def _isFloat(v):
		return v-floor(v)>0

	def __repr__(self):
		return f"{self._numerator}/{self._denominator}"
	
	def toFloat(self):
		return self.numerator/self.denominator
	
	@classmethod
	def __simplifyFrac(cls,numerator,denominator):
		if(denominator==0):
			numerator,denominator = [1,0]
		else:
			gcd = cls.__gcd(denominator,numerator)
			numerator,denominator = [int(numerator/gcd),int(denominator/gcd)]
		return [numerator,denominator]
	
	@staticmethod
	def getSimplifyFrac(frac):
		return Fraction(*Fraction.__simplifyFrac(frac.numerator,frac.denominator))

	@staticmethod
	def __gcd(a,b):
		t = 0
		while(b!=0):
			t,a = a%b,b
			b = t
		return a
	
	def print(self):
		print(self._numerator,self._denominator,sep = '\n----\n',end = '\n\n')

	# 加减乘除
	def __add__(self,other):
		gcd = self.__gcd(self._denominator,other._denominator)
		denominator = (self._denominator*other._denominator)/gcd
		numerator = denominator/self._denominator*self._numerator+denominator/other._denominator*other._numerator
		numerator,denominator = self.__simplifyFrac(numerator,denominator)
		return Fraction(numerator,denominator)

	def __sub__(self,other):
		gcd = self.__gcd(self._denominator,other._denominator)
		denominator = (self._denominator*other._denominator)/gcd
		numerator = denominator/self._denominator*self._numerator-denominator/other._denominator*other._numerator
		numerator,denominator = self.__simplifyFrac(numerator,denominator)
		return Fraction(numerator,denominator)

	def __mul__(self,other):
		numerator = self._numerator*other._numerator
		denominator = self._denominator*other._denominator
		numerator,denominator = self.__simplifyFrac(numerator,denominator)
		return Fraction(numerator,denominator)

	def __truediv__(self,other):
		# print(f'[Info] self:{self.__repr__}')
		# print(f'[Info] other:{other.__repr__}')
		numerator = self._numerator*other._denominator
		denominator = self._denominator*other._numerator
		numerator,denominator = self.__simplifyFrac(numerator,denominator)
		return Fraction(numerator,denominator)

def main():
	frac1 = Fraction(4,5)
	frac2 = Fraction(2,3.1)
	frac3 = Fraction(1.2,3)
	frac4 = Fraction('2.3/2')
	for i in range(1,5):
		eval(f'frac{i}.print()')

	frac5 = Fraction('0/0')
	frac5.print()
	frac3.numerator = 60
	frac3.print()
	Fraction.getSimplifyFrac(frac3).print()
	print(frac3)
	frac6 = Fraction(1,0)
	frac6.print()
	print(frac2.toFloat())

if __name__ == '__main__':
	main()