loop = True while (loop): print("\n----LIBRARY MANAGEMENT SYSTEM----\n") print("THE FOLLOWING ARE ITEMS IN THE LIBRARY") print("1. Book \n2. Audiobook \n3. Film") print("\nFOLLOWING ARE ACTIONS YOU CAN MAKE ON ITEMS IN THE LIBRARY: ") print("1. ADD \n2. SELL \n3. RENT \n4. LEND \n5. VIEW ITEM") action = int( input("\nPLEASE ENTER THE NUMBER OF THE OPERATION YOU WANT TO MAKE: ")) print("---------------------------------------------------------\n") if action == 1: new = Librarian() new.add(books, audiobooks, films) if action == 2: buy = Librarian() buy.sell(books, audiobooks, films) if action == 3: torent = Librarian() torent.rent(audiobooks, films) if action == 4: borrow = Librarian() borrow.lend(books) if action == 5: viewitem = Librarian() viewitem.view(books, audiobooks, films)