Hi Ahmed

import sys
from pathlib import Path
# Potential extension: make contacts an object


def get_filename():
    filename = input("\nFilename: ")
    if filename[-4:] != ".txt":
        filename += ".txt"
    return filename


def get_existing_filename():
    while True:
        filename = get_filename()
        file = Path(filename)
        if file.is_file():
            return filename
        else:
            print(f"'{filename}' does not exist in this directory.")


def find_contact():
    filename = get_existing_filename()
    file = open(filename, "r")
    contact_name = input("\nContact name: ").lower()
    lines = file.read().splitlines()
    found = False
    for line in lines:
        if contact_name in line:
            print(f"{contact_name.title()}: {line[line.index(':') + 1:]}")
            found = True
            break
    if not found:
        print(f"'{contact_name.title()}' was not found in the contact book.")
    file.close()
    menu()


def create_contact():
    while True:
        print("\nCreate contact\n1) Add to existing contact book\n2) Create new contact book\n")
        try:
            option = int(input("Option: "))
            if option == 1:
                filename = get_existing_filename()
                file = open(filename, "a")
                contact_name = input("\nContact name: ").lower()
                while True:
                    try:
                        phone_number = input("\nPhone number: ")
                        int(phone_number)
                        break
                    except ValueError:
                        print("Please enter a valid phone number.")
                file.write(f"{contact_name}:{phone_number}\n")
                file.close()
                print(f"Added {contact_name.title()} to the contact book.")
                break
            elif option == 2:
                while True:
                    filename = get_filename()
                    file = Path(filename)
                    if file.is_file():
                        print("Please enter a filename that does not exist.")
                    else:
                        break
                file = open(filename, "w+")
                file.close()
                print(f"Created a new contact book called '{filename}'.")
                break
            else:
                print("Please choose an option between 1 and 2.")
        except ValueError:
            print("Please choose an option between 1 and 2.")
    menu()


def menu():
    while True:
        print("\nMenu\n1) Find contact\n2) Create contact\n3) Quit\n")
        try:
            option = int(input("Option: "))
            if option == 1:
                find_contact()
            elif option == 2:
                create_contact()
            elif option == 3:
                sys.exit()
            else:
                print("Please choose an option between 1 and 3.")
        except ValueError:
            print("Please choose an option between 1 and 3.")


print("Contact Book")
menu()