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首页 > 解决方案 > 第 34 行的 elif 语句出现错误。它说语法无效。我尝试将缩进和 elif 语句更改为 if else

python - 第 34 行的 elif 语句出现错误。它说语法无效。我尝试将缩进和 elif 语句更改为 if else

问题描述

class book:
    def __init__(self,aut, pub, p, cp=0):
        self.author=aut
        self.publisher=pub
        self.price=p
        self.copies=cp
    def get_author(self):
        return self._author
    def set_author(self, aut):
        self._author=aut
        return
    author=property(get_author, set_author)
    def get_publisher(self):
        return self._publisher
    def set_publisher(self, pub):
        self._publisher=pub
        return
    publisher=property(get_publisher, set_publisher)
    def get_price(self):
        return self._price
    def set_price(self,p):
        self._price=p
        return
    price=property(get_price, set_price)
    def get_copies(self):
        return self._copies
    def set_copies(self,cp):
        self._copies=cp
        return
    copies=property(get_copies, set_copies) 
    def get_royalty(self):
        if self.copies<=500:
            self._royalty=self.copies*self.price*10/100
    elif:
         self.copies<=1000:
         self._royalty=500*self.price*10/100+ \
        (self.copies-500)*self.price*12.5/100
    else:
        self._royalty=500*self.price*10/100 + \
        500*self.price*12.5/100 + \
        (self.copies-1000)*self.price*15/100
        return self._royalty
class ebook(book):
    def __init__(self, aut, pub, p, cp=0, form=None):
    super().__init__(aut,pub,p,cp)
    self.format=form
    def get_format(self):
        return self._format
    def set_format(self, form):
        self._format=form
        return
    format=property(get_format, set_format)
    def get_royalty(self):
        ryl=super().get_royalty() 
        ryl=ryl-ryl*12/100
        self._royalty=ryl
        return self._royalty
 
if __name__== "__main__":
    print ('print book example')
    b1=book('aa','ss',100,600)
    print ("Royalty earned : ", b1.get_royalty())
    print ('ebook example')
    e1=ebook('aa','ss',100, 3, 'PDF')
    print ('Royalty earned' , e1.get_royalty())

第 34 行的 elif 语句出现错误。它说语法无效。我尝试更改缩进并将 elif 语句更改为 if else。我尝试更改 def 和 return 语句的缩进以及 elif 语句，但没有任何改进。我也尝试合并代码块，但这没有帮助。我应该怎么做才能无错误地运行代码？

标签： pythonsyntaxsyntax-errorindentationkeyword

解决方案

我修复了代码的缩进，现在语法错误消失了，一切都按预期工作：

class Book:

    def __init__(self, aut, pub, p, cp=0):
        self._author = aut
        self._publisher = pub
        self._price = p
        self._copies = cp

    def get_author(self):
        return self._author

    def set_author(self, aut):
        self._author = aut

    author = property(get_author, set_author)

    def get_publisher(self):
        return self._publisher

    def set_publisher(self, pub):
        self._publisher = pub

    publisher = property(get_publisher, set_publisher)

    def get_price(self):
        return self._price

    def set_price(self, p):
        self._price = p

    price = property(get_price, set_price)

    def get_copies(self):
        return self._copies

    def set_copies(self, cp):
        self._copies = cp

    copies = property(get_copies, set_copies)

    def get_royalty(self):
        if self._copies <= 500:
            self._royalty = self._copies * self._price * 10 / 100

        elif self._copies <= 1000:
            self._royalty = 500 * self._price * 10 / 100 + \
                    (self._copies - 500) * self._price * 12.5 / 100

        else:
            self._royalty = 500 * self._price * 10 / 100 + \
                500 * self._price * 12.5 / 100 + \
                (self._copies - 1000) * self._price * 15 / 100
        return self._royalty


class Ebook(Book):

    def __init__(self, aut, pub, p, cp=0, form=None):
        super().__init__(aut, pub, p, cp)
        self._format = form

    def get_format(self):
        return self._format

    def set_format(self, form):
        self._format = form

    format = property(get_format, set_format)

    def get_royalty(self):
        ryl = super().get_royalty()
        ryl = ryl - ryl * 12 / 100
        self._royalty = ryl
        return self._royalty


if __name__ == "__main__":
    print('print book example')
    b1 = Book('aa', 'ss', 100, 600)
    print("Royalty earned : ", b1.get_royalty())
    print('ebook example')
    e1 = Ebook('aa', 'ss', 100, 3, 'PDF')
    print('Royalty earned', e1.get_royalty())

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