class Book():

     def __init__(self,ISBN,Ftile,Author,Publisher):

         self.ISBN = ISBN

         self.Ftile = Ftile

         self.Author = Author

         self.Publisher = Publisher

     def show(self):

         print(self.ISBN,self.Ftile,self.Author,self.Publisher)

 class BookList():

     def __init__(self):

         self.books = []

     def show(self):

         print(self.ISBN, self.Ftile, self.Author, self.Publisher)

         for i in self.books:

             self.show()

     def __insert(self,s):

         i = 0

         while(i<len(self.books) and s.ISBN > self.books[i]):

             i=i+1

         self.books.insert(i,s)#指定位置添加一个元素

         print("ok")

     def __update(self,s):

         i = 0

         while(i<len(self.books) and s.ISBN != self.books[i]):

             i=i+1

         if(s.ISBN==self.books[i]):

             del self.books[i]

             self.books.insert(i,s)

             print("-- update @ ok --")

         else:

             print("--error--")

     def __delete(self):

         while(i<len(self.books) and s.ISBN != self.books[1]):

             i=i+1

         if(s.ISBN ==self.books[i]):

             del self.books[i]

             print("-- delete @ ok --")

         else:

             print("--error--")

     def insert(self):

         ISBN = input('ISBN:')

         Ftile = input('Ftile:')

         Author = input('Author:')

         Publisher = input('Publisher:')

         if (ISBN!='' and Ftile!=''):

               self.__insert(Book(ISBN,Ftile,Author,Publisher))

         else:

             print("--ISBN/Ftile^error--")

     def update(self):

         ISBN = input('ISBN:')

         Ftile = input('Ftile:')

         Author = input('Author:')

         Publisher = input('Publisher:')

         if (ISBN != '' or Ftile != '' or Author!='' or Publisher!=''):

             self.__update(Book(ISBN, Ftile, Author, Publisher))

         else:

             print("---error---")

     def delete(self):

         ISBN = input('ISBN:')

         Ftile = input('Ftile:')

         Author = input('Author:')

         Publisher = input('Publisher:')

         if (ISBN != '' or Ftile != '' or Author != '' or Publisher != ''):

             self.__delete(Book(ISBN, Ftile, Author, Publisher))

         else:

             print("---error---")

     def scan(self):

         while True:

             s = input(">>>")

             if s=='show':

                 self.show()

             elif s=='insert':

                 self.insert()

             elif s=='update':

                 self.update()

             elif s=='delete':

                 self.delete()

             elif s=='exit':

                 break

             else:

                 print(" ---- Error ---- ")

                 return 0

         self.File()

         #print(self.books)   》》》》[<__main__.Book object at 0x0000020B3A08CFD0>]

     def File(self):

         f = open('jiaocai.txt','wt+',encoding = 'utf-8')

         for i in self.books:

             f.write(i.ISBN+'\n')

             f.write(i.Ftile+'\n')

             f.write(i.Author+'\n')

             f.write(i.Publisher+'\n')

         #books = self.books

         #f.write(str(books))#不可用

         f.close()

 Bl=BookList()

 Bl.scan()

 #print(BookList.books)