使用Python的私有和公共屬性

Question

我在我的Python書中發現了這個問題，但我在使用私有和公共屬性打印作者，標題和副本數方面遇到困難。

下面是說明：

class Book(object): 
def __init__(self,author,title,copies): 
#The __init__ method must accept arguments for 
#the author (private attribute) 
#the title (public attribute) and 
#the number of copies (private atrribute) 

def display(self): 
#The display method must display the information 
#for the book, that is the author, title and number of copies 
#available 

def sell_book(self,sold): 
#This method must extract from the number of copies available 
#the number of copies sold. 
#Test that the user doesn't sell more copies than there are 
#available. 
#Display a suitable message if it was the last copy sold 

def main(): 
#create an instance of the Book class 
myBook = Book(author="JB Wellington", title="The digital divide", 
copies=40) 
myBook.sell_book(sold=3) 
myBook.display() 
#main 
main() 

這裏是我的代碼：

class Book(object): 
    def __init__(self, author, title, copies): 
     self.__author = author 
     self.title = title 
     self.__copies = copies 

def display(self): 
    print "author:", self.__author, "\n" 
    print "Tilte:", self.titile, "\n" 
    print "Number of copies:", self.__copies, "\n" 


def sell_book(self, sold): 
    if self.__copies < 0 
     print"The last copie sold" 


def main(): 
    #create an instance of the Book class 
    myBook = Book(author="JB Wellington", titile="The digital divide", copies = 40) 
    myBook.sell_book(sold=3) 
    myBook.display() 
#main 
    main() 

Answer 1

是，你有一個不必要的{TAB}前主）的問題（？ 它應該是在行的開頭