class BankAccount: """A simple bank account.""" _total_accounts = 0 # class variable def __init__(self, owner: str, balance: float = 0.0): self.owner = owner self._balance = balance BankAccount._total_accounts += 1
def greet(name: str, excited: bool = False) -> str: """Return a greeting.""" message = f"Hello, name" return message.upper() + "!!!" if excited else message print(greet("Maria", excited=True)) # HELLO, MARIA!!! def log(level, *messages, **metadata): print(f"[level.upper()]", *messages, metadata) log("info", "User login", "IP 192.168.1.1", user="alice") [INFO] User login IP 192.168.1.1 'user': 'alice' 4. Classes – Modeling in Python Code Python classes are straightforward. No need for getters/setters (use @property when needed). in python code
def deposit(self, amount: float) -> None: if amount <= 0: raise ValueError("Deposit must be positive") self._balance += amount class BankAccount: """A simple bank account
@classmethod def total_accounts(cls) -> int: return cls._total_accounts acc = BankAccount("Elena", 1000) acc.deposit(500) print(acc.balance) # 1500 print(BankAccount.total_accounts()) # 1 5. Error Handling – Fail Gracefully try/except/else/finally – the else runs only if no exception occurred. No need for getters/setters (use @property when needed)