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我正在编写一个程序来划分有理数，但我希望它能够处理分数。我想将 1 除以 1/3，但我的程序在处理整数时遇到错误。我试图通过几种不同的方式将整数转换为有理数，但没有任何效果。任何帮助或指导将不胜感激。

这是我不断收到的错误，它是代码底部断言语句中的标志。

回溯（最后一次调用）：文件“E:\Python\Rational number extension excercise.py”，第 47 行，在断言 Rational(3) == 1 / r3，“除法测试失败。” TypeError：不支持的操作数类型/：'int'和'Rational'

class Rational(object):
 """ Rational with numerator and denominator. Denominator
 parameter defaults to 1"""

 def __init__(self,numer,denom=1):  
     #test print('in constructor')
        self.numer = numer
        self.denom = denom

 def __truediv__(self,param):
    '''divide two rationals'''
    #test print('in truediv')
    if type(param) == int:  # convert ints to Rationals
        param = Rational(param)
    if type(param) == Rational:
        # find a common denominator (lcm)
        the_lcm = lcm(self.denom, param.numer)
        # adjust the param value
        lcm_numer = (the_lcm * param.numer)
        lcm_denom = (the_lcm * param.denom)
        true_param = int(lcm_denom / lcm_numer)
        #print(int(lcm_denom / lcm_numer))
        # multiply each by the lcm, then multiply
        numerator_sum = (the_lcm * self.numer/self.denom) * (true_param)
        #print(numerator_sum)
        #print(Rational(int(numerator_sum),the_lcm))
        return Rational(int(numerator_sum),the_lcm)
    else:
        print('wrong type')  # problem: some type we cannot handle
        raise(TypeError)

 def __rdiv__(self,param):
    '''divide two reversed rationals'''
    # mapping is correct: if "(1) / (x/x)", 1 maps (to 1/1)
    if type(self) == int:
        self.numer = self
        self.denom = 1
    return self.__truediv__(self.numer)
    return self.__truediv__(self.denom)

r1 = Rational(2,3)
r2 = Rational(1,4)
r3 = Rational(1,3)

assert Rational(2) == r1 / r3, "Division test failed."
assert Rational(3) == 1 / r3, "Division test failed."
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1 回答 1

2 
 def __rdiv__(self,param):
    '''divide two reversed rationals'''
    # mapping is correct: if "(1) / (x/x)", 1 maps (to 1/1)
    if type(self) == int:
        self.numer = self
        self.denom = 1

type(self) == int永远不会评估为 True：如果您在 上运行__rdiv__，则Racionalself 将始终为Racional. 您需要进行测试param，即除法的左侧（在您的示例中为 1）。

于 2014-04-07T13:42:33.433 回答