app.py

import pprint


def menu():
    options = [
        "0. Add a contact",
        "1. Search contact",
        "2. Delete a contact",
        "3. View all contacts",
        "4. Quit",
    ]
    for option in options:
        print(option)


def main():
    contacts = {"John": "1342343232", "Sara": "9876543210"}

    while True:
        menu()
        choice = int(input("Enter option number: "))
        if choice >= 0 and choice <= 4:
            if choice == 0:
                while True:
                    name = input("Enter name for the new contact: ")
                    if name == "q":
                        break
                    if name in contacts:
                        print("A contact with that name already exists!")
                        continue
                    phone_number = input("Enter a phone number: ")
                    contacts[name.lower()] = phone_number
                    print("Contact added!")
                    break
            elif choice == 1:
                while True:
                    search_query = input("Search: ")
                    if search_query == "q":
                        break
                    if search_query.lower() in contacts:
                        print(pprint.pformat(contacts[search_query.lower()]))
                        break
                    print("No contact with that name exists!")
                    continue
            elif choice == 2:
                while True:
                    name = input("Enter name for the new contact: ").lower()
                    if name == "q":
                        break
                    if name in contacts:
                        del contacts[name]
                        print("Contact deleted!")
                        break
                    print("No contact with that name exists!")
                    continue
            elif choice == 3:
                print(pprint.pformat(contacts))
            elif choice == 4:
                exit()
        else:
            continue


main()