This is the final assignment for the Python Object-Oriented Programming course. In this assignment, you will learn the following useful skills:
- Serialization and deserialization of data using pickle
- Working with files
Technical Description of the Task
โ In this assignment, you need to add functionality to save the address book to disk and restore it from disk.
To do this - you need to choose the pickle data serialization/deserialization protocol and implement methods that allow you to save all data to a file and load it from a file.
The main goal is that the application does not lose data after exiting the application and restores it from a file when launched. The address book that we worked with in the previous session should be saved.
Implement functionality to save the state of AddressBook to a file when closing the program and restore the state when it starts.
Code Examples that will be useful:
Serialization with pickle
import pickle
def save_data(book, filename="addressbook.pkl"):
with open(filename, "wb") as f:
pickle.dump(book, f)
def load_data(filename="addressbook.pkl"):
try:
with open(filename, "rb") as f:
return pickle.load(f)
except FileNotFoundError:
return AddressBook() # Return a new address book if the file is not found
Integration of saving and loading into the main loop
def main():
book = load_data()
# Main program loop
save_data(book) # Call before exiting the program
Instructions:
- Create a file named
addressbook.py
- Implement the
AddressBook
class as described in the previous assignment. - Implement the
save_data
andload_data
functions as shown in the code examples above. - Modify the
main
function to load the address book from a file at the beginning, save the address book to a file before exiting, and call the main program loop in between. - Test your code by adding a few contacts to the address book, saving it to a file, exiting the program, restarting the program, and loading the address book from the file.
Additional Notes:
- Make sure to use a consistent filename for saving and loading the address book.
- You may want to add error handling to your code to deal with potential problems such as file not found or serialization errors.
- Consider using a different serialization format if pickle is not suitable for your needs.