backend/app/db/database.py

import os
from dotenv import load_dotenv

load_dotenv()

db_type = os.getenv("DB_TYPE")


if db_type == "mongodb":
    from .database_mongodb import get_user_by_username, create_user, save_file, get_user_files
else:
    from .database_dynamodb import get_user_by_username, create_user, save_file, get_user_files
    
get_user_by_username
create_user
save_file
get_user_files