registration system | Python Fiddle

import hashlib
import json
import os

def load_db(db_path):
    # If the file provided does not exist, return an empty dict (a blank database)
    if not os.path.isfile(db_path):
        return {}
    with open(db_path, 'r') as reader:
        db = reader.read()
        return json.loads(db)

def login(db_path):
    print("Welcome to Password Generator, please sign in.")
    username = input("Enter username? ")
    password = input("Enter password? ")
    
    db = load_db(db_path)
    valid = True

# 1. Does the provided username exist?
    if db.get(username):
        user_pass = db.get(username)['secret']
        
        # 2. Ok, we know the user's hashed password. Now let's hash the input and compare:
        if hashlib.sha224(password.encode('utf-8')).hexdigest() != user_pass:
            valid = False
    else:
        valid = False
    
    if valid:
        print("You are logged in!")
    else:
        print("Invalid Password! or Username!")

def register(db_path):
    selection = input("What to do? (register/login) ")
    selection = selection.lower()

if selection == 'register':
        user_info = {
            'name': None,
            'secret': None,
            'email': None,
        }
        
        user_info['name'] = input("Username? ")
        user_info['secret'] = input("Password? ")
        user_info['email'] = input("What's your email address? ")
        
        # Load the database
        db = load_db(db_path)

# Check if the provided username is already taken
        if db.get(user_info['name']):
            raise Exception('Username already taken ({})'.format(user_info['name']))

# If it's not taken, create a slot for it in the DB
        db[user_info['name']] = user_info
        
        # ...but be sure to hash the password:
        user_info['secret'] = hashlib.sha224(user_info['secret'].encode('utf-8')).hexdigest()

# Update the database file
        with open(db_path, 'w') as writer:
            print('Updating the contents of the datase')
            print(db)
            writer.write(json.dumps(db))

elif selection == 'login':
        login(db_path)
    else:
        print('Invalid option. No soup for you!')

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