python question

import csv

import json

import pathlib

from operator import itemgetter

def load_db(path):

"""Load books from the database csv file.

Args:

path (pathlib.Path): path to the csv file

Returns:

list: a list of books where each book is a dictionary

"""

pass

def save_db(books, path):

"""Write a list of books to csv file.

Args:

books (list): a list of books where each book is a dictionary

path (pathlib.Path): the path to the csv file

Returns:

None

"""

pass

def fullname(fname, lname):

"""Join arguments into a full name"""

return f"{fname}, {lname}"

def id_generator(books):

"""Generate the id of the next book to be added to

the database.

Ids are assigned incrementally, so we take the current

largest id in the database and add 1 to get the next id.

This is useful when creating new books, so that we don't

have to guess what the next id should be.

"""

return max(int(book['id']) for book in books) + 1

def display_books(books):

if books:

for book in books:

print(format_book(book))

else:

print('There are no books to display')

def format_book(book):

"""Return a formatted representation of the book"""

pass

def get_book(books, id):

"""Retrieve a single book from the database.

Args:

books (str): a copy of the books db

id (int): the book's unique id

Returns:

dict: the book with the specified id if found

None: if the book was not found

"""

for book in books:

if int(book['id']) == id:

return book

return None

def filter_books(books, key, value):

"""Filter books by the specified key.

Args:

books (list): a copy of the books db

key (str): the filter key, one of the keys

of the book dictionary

value (any): the filter criterion

Returns:

list : a list of books matching the filter criteria

"""

pass

def update_book(books, id):

"""Edit the details of the book matching the specified id.

Args:

books (list): a copy of the books db

id (int): the unique id of the book to update

Returns:

list: a list of books containing the updated book

"""

book = get_book(books, id)

if not book:

print(f"The book with id: {id} was not found")

return False

for key in book.keys():

new_value = input("Press key to keep the old value. "

f"Enter {key!r} new value: ").strip()

if new_value:

book[key] = new_value

return books

def display_main_menu():

print('Please choose an action to perform: ')

print('1. Show all books')

print('2. Search books')

print('3. Add books')

print('4. Update book')

print('5. Delete book')

print('6. Quit')

def perform_action(action):

db_path = 'books_db.csv'

books = load_db(db_path)

if action == 1:

# implement the following display options:

# 1. Display all books unsorted

# 2. Filter books according to some criteria

# 3. Display books sorted according to some criteria

display_books(books)

if action == 2:

# perform search action

display_books(books)

if action == 3:

# Perform add books action

# Add the new books to the book database

# by calling save_db()

pass

if action == 4:

id = int(input('Enter book id: ').strip())

books = update_book(books, id)

if books:

save_db(books, db_path)

if action == 5:

# Perform delete book action

# If deletion is successful,

# save the updated list of books to the database

pass

def main():

while True:

display_main_menu()

action = int(input('> ').strip())

if action == 6:

break

else:

perform_action(action)

if __name__ == '__main__':

main()

- Unsorted: list all the books in the database without first sorting them - Sorted: list all the books in the database sorted according to some key - Filtered: list only books matching specified filtering criteria 2. Searching the database. The following options should be supported: - Search by title: Return all the books whose title include any of the words in the search term - Search by author's name: The search term for this option is a single name to match either the author's first or last name. All books matching the criteria are returned. 3. Creating new books. This option supports creating multiple books at once. 4. Updating a book. This option supports editing one or multiple fields of the book 5. Deleting a book. 6. CRUD operations, i.e. create, update, delete, should be immediately followed by saving the current contents of the database to the underlying CSV or JSON storage. Part I 1. Complete Part I and submit your program to Books Database Part I submission folder on the Learning Hub 2. Decide which underlying storage type you want to use for your implementation, then download the corresponding database file, either books_db.csv or books_db. .json. Feel free to try both. 3. Download the books_database.py file and enter your code there. This file contains a partial implementation of the program with a the following functions fully implemented: - main(): this function has a single job, which is to display the main menu and let the user select an action to perform. It then calls perform_action () - display_main_menu(0: displays the options of the main menu - update_book0: updates details of a single book - id_generator(): operations such as updates and deletes require retrieval of a single book based on a unique key. This function generates the id for the next book to be added to the database. - display_books(: prints a list of books on the screen - get_book(): retrieves a single book from the database given a unique id - fullname(): returns the author's full name 4. You should implement the following functions: - load_db(): takes the path to the database file as argument, reads the contents and returns a list of books - save_db(): takes the path to the database file as argument, and writes a list of books to the file. This function overwrites the database file each time it is called. - format_book(0: takes a book as an argument and returns a formatted representation of the book - filter_books(): takes a list of books and the filter criteria as arguments, and returns a list of books matching the filter criteria. The filter criteria is a combination of a key and value. Example: filter_books(books, 'author', 'Roy') 5. The perform_action () function is the heart of this program, but it is not yet fully implemented. For Part I you should only implement the first two options action 1, that is: - Display all books unsorted - Display books filtered according to some criteria. You can filter books based on the author, genre, publisher or year of publication. You should get the user to indicate how to filter the books by providing a key and value. Example: filter_books(books, 'genre', 'fiction') The God of Small Things Author: Arundhati, Roy Genre: fiction Publisher: Fourth Estate Year: 1997 ID: 1 Cryptonomicon Author: Neal, Stephenson Genre: fiction Publisher: Avon Books Year: 1999 ID: 2