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<\/a><\/div>\nThis program would not really be difficult as the design would be modular with different functions to perform different operations. Let’s take a look at all the functions.<\/p>\n
<\/p>\n
1. SaveBook(book)<\/b>
\nThis function takes a book record as parameter and writes the record into the file
\n<\/p>\n# FUNCTION TO SAVE BOOK TO FILE<\/span>\r\ndef<\/span> SaveBook<\/span>(book):\r\n f =<\/span> open<\/span>(\"BookData.csv\"<\/span>,\"a+\"<\/span>)\r\n f.<\/span>write(book[0<\/span>] +<\/span> ','<\/span> +<\/span> book[1<\/span>] +<\/span> ','<\/span> +<\/span> book[2<\/span>] +<\/span> ','<\/span> +<\/span> book[3<\/span>] +<\/span> '<\/span>n<\/span>'<\/span>)\r\n f.<\/span>close()<\/pre>\n <\/p>\n
2. GetRecord()<\/b>
\nThis function accept id as parameter, then searches the database to retrieve the record with the given id<\/p>\n
<\/p>\n
# FUNCTION TO RETRIEVE A SINGLE BOOK RECORD FROM THE DATABASE<\/span>\r\ndef<\/span> GetRecord<\/span>(input_id):\r\n with<\/span> open<\/span>(\"BookData.csv\"<\/span>,\"r\"<\/span>) as<\/span> f:\r\n for<\/span> line in<\/span> f:\r\n line =<\/span> line.<\/span>rstrip()\r\n id<\/span>,title,author,isbn =<\/span> line.<\/span>split(\",\"<\/span>)\r\n if<\/span> (id<\/span> ==<\/span> input_id):\r\n return<\/span> line<\/pre>\n <\/p>\n
3. AddBook()<\/b>
\nThis function prompts the user for book details. Then it calls the SaveBook() function to save the book to file<\/p>\n
<\/p>\n
# FUNCTION TO ADD A BOOK TO THE DATABASE<\/span>\r\ndef<\/span> AddBook<\/span>():\r\n Book =<\/span> namedtuple(\"Book\"<\/span>, \"ID Title Author ISBN\"<\/span>)\r\n id<\/span> =<\/span> input<\/span>(\"Enter the ID: \"<\/span>)\r\n title =<\/span> input<\/span>(\"Enter title of book: \"<\/span>)\r\n author =<\/span> input<\/span>(\"Enter name of author: \"<\/span>)\r\n isbn =<\/span> input<\/span>(\"Enter ISBN: \"<\/span>)\r\n newBook =<\/span> Book(id<\/span>, title, author, isbn)\r\n SaveBook(newBook)\r\n print<\/span>(\"Book was added successfullly\"<\/span>)<\/pre>\n <\/p>\n
4. DisplayBook()<\/b>
\nThis function prompts the user for an id, then it calls to the GetRecord() function to retrieve the book corresponding that id and then displays the book details<\/p>\n
<\/p>\n
# FUNCTION DISPLAY DETAILS OF A PARTICULAR BOOK<\/span>\r\ndef<\/span> DisplayBook<\/span>():\r\n input_id =<\/span> input<\/span>(\"Enter the ID of book to display: \"<\/span>)\r\n id<\/span>,title,author,isbn =<\/span> GetRecord(input_id).<\/span>split(\",\"<\/span>)\r\n if<\/span> (id<\/span> ==<\/span> input_id):\r\n print<\/span>('{0: <5}'<\/span>.<\/span>format(id<\/span>) +<\/span> '<\/span>n<\/span>{0: <35}'<\/span>.<\/span>format(title) +<\/span> '<\/span>n<\/span>{0: <25}'<\/span>.<\/span>format(author) +<\/span> '<\/span>n<\/span>{0: <15}'<\/span>.<\/span>format(isbn))\r\n<\/pre>\n <\/p>\n
5. DeleteBook()<\/b>
\nThis function prompt the user for an id, then it deletes the record corresponding to that id from the file<\/p>\n
<\/p>\n
# FUNCTION TO DELETE A BOOK FROM THE DATABASE<\/span>\r\ndef<\/span> DeleteBook<\/span>():\r\n input_id =<\/span> input<\/span>(\"Enter the ID of the book to delete: \"<\/span>)\r\n f =<\/span> open<\/span>(\"BookData.csv\"<\/span>,\"r+\"<\/span>)\r\n d =<\/span> f.<\/span>readlines()\r\n f.<\/span>seek(0<\/span>)\r\n for<\/span> line in<\/span> d:\r\n record =<\/span> line.<\/span>rstrip()\r\n id<\/span>,title,author,isbn =<\/span> record.<\/span>split(\",\"<\/span>)\r\n if<\/span> id<\/span> !=<\/span> input_id:\r\n f.<\/span>write(line)\r\n f.<\/span>truncate()\r\n f.<\/span>close()\r\n print<\/span>(\"Book was successfully deleted from the database!\"<\/span>)<\/pre>\n <\/p>\n
6. ViewBooks()<\/b>
\nThis function displays all the books in the database.<\/p>\n
<\/p>\n
# FUNCTION TO VIEW ALL BOOKS IN THE DATABASE<\/span>\r\ndef<\/span> ViewBooks<\/span>():\r\n with<\/span> open<\/span>(\"BookData.csv\"<\/span>,\"r\"<\/span>) as<\/span> f:\r\n for<\/span> line in<\/span> f:\r\n line =<\/span> line.<\/span>rstrip()\r\n id<\/span>,title,author,isbn =<\/span> line.<\/span>split(\",\"<\/span>)\r\n if<\/span> not<\/span> line: continue<\/span>\r\n print<\/span>('{0: <5}'<\/span>.<\/span>format(id<\/span>) +<\/span> '{0: <35}'<\/span>.<\/span>format(title) +<\/span> '{0: <25}'<\/span>.<\/span>format(author) +<\/span> '{0: <15}'<\/span>.<\/span>format(isbn))<\/pre>\n <\/p>\n
7. Search()<\/b>
\nThis function prompts for a search criteria. It then searches through the all the records to find a record that matches with the given criteria.<\/p>\n
<\/p>\n
# FUNCTION TO SEARCH FOR A BOOK IN THE DATABASE<\/span>\r\ndef<\/span> Search<\/span>():\r\n criteria =<\/span> input<\/span>(\"Enter a search criteria: \"<\/span>)\r\n with<\/span> open<\/span>(\"BookData.csv\"<\/span>,\"r\"<\/span>) as<\/span> f:\r\n for<\/span> line in<\/span> f:\r\n line =<\/span> line.<\/span>rstrip()\r\n if<\/span> line.<\/span>upper().<\/span>find(criteria.<\/span>upper()) !=<\/span> -<\/span>1<\/span>:\r\n id<\/span>,title,author,isbn =<\/span> line.<\/span>split(\",\"<\/span>)\r\n print<\/span>('{0: <5}'<\/span>.<\/span>format(id<\/span>) +<\/span> '<\/span>n<\/span>{0: <35}'<\/span>.<\/span>format(title) +<\/span> '<\/span>n<\/span>{0: <25}'<\/span>.<\/span>format(author) +<\/span> '<\/span>n<\/span>{0: <15}'<\/span>.<\/span>format(isbn))<\/pre>\n <\/p>\n
8. GetTotal()<\/b>
\nThis function counts the total number of books in the database.<\/p>\n
<\/p>\n
# GET THE TOTAL NUMBER OF BOOKS<\/span>\r\ndef<\/span> GetTotal<\/span>():\r\n return<\/span> sum<\/span>(1<\/span> for<\/span> line in<\/span> open<\/span>('BookData.csv'<\/span>))<\/pre>\n <\/p>\n
9. DisplayMenu()<\/b>
\nThis function displays the menu and allows user to make a choice of operations to perform.<\/p>\n
<\/p>\n
#FUNCTION TO DISPLAY THE MENU<\/span>\r\ndef<\/span> DisplayMenu<\/span>():\r\n print<\/span>(\"CHOOSE AN OPERATION. \"<\/span>)\r\n print<\/span>(\"1. ADD A BOOK\"<\/span>)\r\n print<\/span>(\"2. DISPLAY BOOK DETAILS\"<\/span>)\r\n print<\/span>(\"3. DELETE A BOOK\"<\/span>)\r\n print<\/span>(\"4. VIEW BOOKS\"<\/span>)\r\n print<\/span>(\"5. SEARCH FOR BOOK\"<\/span>)\r\n print<\/span>(\"6. GET TOTAL NUMBER\"<\/span>)\r\n
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