In this project, you will extend Contact Book (Part 1) to save and load contacts from a file. Your contact data will now persist between program runs.

Your program must meet the following specifications:

• Start by loading contacts from a file (if it exists)
• Keep all functionality from Part 1: add, view, search, delete contacts
• When user quits, save all contacts to a file
• Handle errors gracefully (missing file, corrupted data)
• Use JSON format to store contacts

For example:

=== Contact Book ===
Loaded 2 contacts from file.

Contact Book Menu
1. Add contact
2. View all contacts
3. Search for contact
4. Delete contact
5. Quit

Choice: 1
Enter name: Bob
Enter phone: 555-5678
Enter email: [email protected]
Enter address: 456 Oak St

Contact saved!

Choice: 5
Saving contacts to file...
Goodbye!

The contacts.json file would contain:

{
  "Alice": {"phone": "555-1234", "email": "[email protected]", "address": "123 Main St"},
  "Bob": {"phone": "555-5678", "email": "[email protected]", "address": "456 Oak St"}
}

Working with Files and JSON

You can read a JSON file:

import json

with open("contacts.json", "r") as file:
    contacts = json.load(file)

You can write a JSON file:

import json

with open("contacts.json", "w") as file:
    json.dump(contacts, file)

You can handle file errors:

import json

try:
    with open("contacts.json", "r") as file:
        contacts = json.load(file)
except FileNotFoundError:
    print("No saved contacts found. Starting fresh.")
    contacts = {}

Example Code

import json

def load_contacts():
    # TODO: Try to load contacts from "contacts.json"
    # TODO: If file doesn't exist, return empty dictionary
    # TODO: If file is corrupted, return empty dictionary and show error
    pass

def save_contacts(contacts):
    # TODO: Save contacts to "contacts.json" in JSON format
    # TODO: Show confirmation message
    pass

def add_contact(contacts):
    # TODO: Get name and details, add to dictionary, print confirmation
    pass

def view_all_contacts(contacts):
    # TODO: Loop through contacts and print each one, handle empty book
    pass

def search_contact(contacts):
    # TODO: Search by name, print info if found or error if not
    pass

def delete_contact(contacts):
    # TODO: Delete by name, print confirmation or error
    pass

# Main program
contacts = load_contacts()

while True:
    print("\n=== Contact Book Menu ===")
    print("1. Add contact")
    print("2. View all contacts")
    print("3. Search for contact")
    print("4. Delete contact")
    print("5. Quit")
    
    choice = input("\nChoice: ")
    
    if choice == "1":
        add_contact(contacts)
    elif choice == "2":
        view_all_contacts(contacts)
    elif choice == "3":
        search_contact(contacts)
    elif choice == "4":
        delete_contact(contacts)
    elif choice == "5":
        save_contacts(contacts)
        print("Goodbye!")
        break
    else:
        print("Invalid choice. Try again.")