Question

I have a database saved as a list of tuples, and every tuple has 4 elements. The first element is the book’s number, the second element is the book’s name, the third element is the book’s author, and the forth element is the book’s publishing year.

I need a function called findBook(L, keyword), that receives the books as a list of tuples, keyword as a string, and returns all the tuples of books that have keyword in them.
The tuple of the book should be like this:

(BookNumber, BookName, Author, YearPublished)

How to write a search engine that will help us find these certain books?

I’ve tried to start with this, but it isn’t working:

def findBook(L,keyword):

    for i in L:
        BookNumber=i[0]
        BookName=i[1]
        Author=i[2]
        YearPublished=i[3]
        i=(BookNumber,BookName,Author,YearPublished)

        if keyword == str(BookName) or keyword==BookNumber or keyword==str(Author) or keyword==str(YearPublished):
            return i

so if i have a harry potter book , and i enter the keyword : “harry” it should return all the whole tuple.

Answer 1

You could iterate over the entries that may have the keyword you’re looking for, grouping them into a list, that shall be returned by the end of the process:

def findBook(L, keyword):

    books = list()
    for book in L:

        book = tuple(entry for entry in book)
        if [i for i in book if str(i).find(keyword) != -1]:
            books.append(book)

    return books

L = [(2,"harry potter and the prisoner of azkaban ","J.K Rowling","1998"),
        (3,"harry potter and the half blood prince","J.K Rowling","2007"),
        (6,"Harry potter and deathly hallows","J.K Rowling","2010"),
        (8,"The secret","someone","2009")]

print findBook(L, "harry")

Output:

[(2, 'harry potter and the prisoner of azkaban ', 'J.K Rowling', '1998'), (3, 'harry potter and the half blood prince', 'J.K Rowling', '2007')]

Notice the third entry was not found because the keyword is “harry” and not “Harry”, to do insensitive case search, use:

def findBook(L, keyword):

    books = list()
    keyword = keyword.tolower()

    for book in L:

        book = tuple(entry for entry in book)
        if [i for i in book if str(i).tolower().find(keyword) != -1]:
            books.append(book)

    return books