This prgram needs at least Python 3.10 because it uses the new match case.
As libarys it uses:
jsonPySimpleGUIdatetimerandom
To add a user, click on Settings and on the new window, click Add user. Then fill out all informations and remember the id. Then click Save.
To edit your profile, write your id to the textfield on the top left. Then you can see your books in a list under it. To edit or delete your profile, click the Profile button Next to the textfield.
To add a book, click on Settings and on the new window, click Add book. Then fill out all informations. Then click Save.
To delete a book, go to the Settings and click on Delete book. Now select a book and delete it with Delete book.
Write your id to the textfield at the top left.
Then you see your borrowed books in the list under it.
Click on one of it to see the informations. Then you can use the Give back and Lengthen buttons.
To borrow a book, search it with the textfield on the top right. Click on a result and then you can use the Borrow button.
Go to the Settings button and click on Overdrawn. There you can see all overdrawn books and when you click one, you can see the user borrowed the book.