我是 Python 新手，但有一些東西讓我對類繼承發瘋，而且我在網上找到的所有解決方案都對我不起作用，而且我無法理解為什么。

我有一個類，Bond例如，我們將投資于他們的期限，將投資的一定數量，最低價格，最低期限和年利率。該子類的LongTerm最短期限為 2 年，最低金額為 250 美元，年利率為 2.5%。

以下代碼正常作業：

class Bond(object):
    def __init__(self,minTerm, term,amount,minPrice,yrlyRate):
        self.term = term
        self.amount = amount
        self.minPrice = minPrice
        self.minTerm = minTerm
        self.yrlyRate = yrlyRate

class LongTerm(Bond):
    def __init__(self, term,amount,minPrice, minAmount = 1000, minTerm = 5, yrlyRate = 0.05):
        self.term = term
        self.amount = amount
        self.minPrice = minPrice
        self.minAmount = minAmount
        self.minTerm = minTerm
        self.yrlyRate = yrlyRate

但是當我使用部分繼承功能時

super().__init__(term,amount,minPrice)

它顯示一個錯誤：

TypeError: __init__() missing 2 required positional arguments: 'minPrice' and 'yrlyRate'

代碼使用super()：

class Bond(object):
    def __init__(self,minTerm, term,amount,minPrice,yrlyRate):
        self.term = term
        self.amount = amount
        self.minPrice = minPrice
        self.minTerm = minTerm
        self.yrlyRate = yrlyRate

class LongTerm(Bond):
    def __init__(self, term,amount,minPrice, minAmount = 1000, minTerm = 5, yrlyRate = 0.05):
        super().__init__(term,amount,minPrice)
        self.term = term
        self.amount = amount
        self.minPrice = minPrice

為什么我不能只部分繼承超類的某些實體？

uj5u.com熱心網友回復：

如果您的子類需要的資訊少于您的超類，那么您可能不需要使用繼承。如果無法修改原件，那么可能composition會更有幫助。

方法1.用通用類繼承

class Bond:
    def __init__(self, minTerm, term, amount, minPrice, yrlyRate):
        self.term = term
        self.amount = amount
        self.minPrice = minPrice
        self.minTerm = minTerm
        self.yrlyRate = yrlyRate


class LongTerm(Bond):
    def __init__(self, term, amount, minPrice, minAmount = 1000, minTerm = 5, yrlyRate = 0.05):
        super().__init__(minTerm, term, amount, minPrice, yrlyRate)
        self.minAmount = minAmount

方法2）。使用覆寫示例和默認引數

class Bond:
    def __init__(self, minTerm, term, amount, minPrice, yrlyRate):
        self.term = term
        self.amount = amount
        self.minPrice = minPrice
        self.minTerm = minTerm
        self.yrlyRate = yrlyRate
    
    def short_term_only(self):
        #do some stuff

        
class LongTerm(Bond):
    def __init__(self, term, amount, minPrice, minAmount = 1000, minTerm = 5, yrlyRate = 0.05):
        # In the event that maybe we don't care about some of the information or methods
        # in the parent we can set them to none or even over-ride the methods
        super().__init__(minTerm, None, None, minPrice, yrlyRate)
        self.minAmount = minAmount
        
    def short_term_only(self):
        raise NotImplementedError

方法 3) 用類組合。對這種方法的關注是，methods對類可用的方法Bond本質上對類不可用LongTerm

class LongTerm:
    def __init__(self, term, amount, minPrice, minAmount = 1000, minTerm = 5, yrlyRate = 0.05):
        self.bond = Bond(minTerm, term, amount, minPrice, yrlyRate)
        self.minAmount = minAmount

uj5u.com熱心網友回復：

我想你需要的是這樣的......

class Bond:
    def __init__(self, term, amount, minPrice, minTerm, yrlyRate):
        self.term = term
        self.amount = amount
        self.minPrice = minPrice
        self.minTerm = minTerm
        self.yrlyRate = yrlyRate

    def __repr__(self):
        return f"Term: {self.term}, Amount: {self.amount}, MinPrice: {self.minPrice}, MinTerm: {self.minTerm}, YearlyRate: {self.yrlyRate}"

class LongTerm(Bond):
    def __init__(self, term, amount, minPrice, minTerm=5, yrlyRate=0.05, minAmount=1000):
        super().__init__(term=term, amount=amount, minPrice=minPrice, minTerm=minTerm, yrlyRate=yrlyRate)
        self.minAmount = minAmount

print(LongTerm(term=1, amount=23, minPrice=45.2))

標籤：Python 蟒蛇-3.x 哎呀 遗产

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