Python - pickle/unpickle

import pickle

# --- functions ---

def pickle_data(email_addresses):
    # Open file for binary writing (it will close automatically)
    with open('email_addresses.dat', 'wb') as email_file:
        # Pickle the dictionary and save it to a file.
        pickle.dump(email_addresses, email_file)


def unpickle_data():
    try:

        # Open file for binary reading (it will close automatically)
        with open('email_addresses.dat', 'rb') as email_file:
            # Unpickle the dictionary and assign to variable
            email_addresses = pickle.load(email_file)

    except FileNotFoundError:

        # Catch exception when file doesn't exist
        email_addresses = {}

    return email_addresses

# --- main ---

# at start unpicle data
data = unpickle_data()

print("data:", data)

data = {'admin@example.com': 'admin'}

# at the end pickle data
pickle_data(data)