basic.py (3-57)
- import statements @3
- DatabaseManager @8 # Manages database connections and queries.
  - __init__ (self, connection_string: str) @11
  - connect (self) @15 # Establish database connection.
     print(f'Connecting to {self.connection_string}')
  - disconnect (self) @19 # Close database connection.
     if self.connection:
      self.connection.close()
  - query (self, sql: str) -> list @24 # Execute a SQL query.
     return []
- UserService @29 # Handles user-related operations.
  - __init__ (self, db: DatabaseManager) @32
  - create_user (self, username: str, email: str) -> int @35 # Create a new user.
     return 1
  - get_user (self, user_id: int) -> Optional[dict] @39 # Retrieve user by ID.
     return None
  - delete_user (self, user_id: int) -> bool @43 # Delete a user.
     return True
- validate_email (email: str) -> bool @48 # Validate email format.
   return '@' in email
- main () @53 # Main entry point.
   db = DatabaseManager('postgresql://localhost/mydb')
   service = UserService(db)
   print('Application started')
