class Book:
    def __init__(self, name, is_borrowed):
        self.name = name
        self.is_borrowed = False

    def borrow(self):
        if self.is_borrowed == True:
            print("이미 대출 중입니다")
        else:
            self.is_borrowed = True
            print("대출완료")

books = Book("어린왕자","생텍쥐페리")
books.borrow()
books.borrow()