Clean Code

ソースコードの依存関係が（具象ではなく）抽象だけを参照しているシステムが最も柔軟である。 Before from abc import ABC, abstractmethod class Order: def __init__(self): self.items = [] self.quantities = [] self.prices = [] self.status = 'open' def add_item(self, name, quantity, price): self.items.append(name) self.quantities.append(quantity) self.prices.append(price) def total_price(self): total = 0 for i in range(len(self.prices)): total += self.quantities[i] * self.prices[i] return total class Authorizer(ABC): @abstractmethod def is_authorized(self) -> bool: pass class Authorizer_SMS(Authorizer): def __init__(self): self.authorized = False def verify_code(self, code): print(f'Verifying SMS code {code}') self.authorized = True def is_authorized(self) -> bool: return self....

包括的なインターフェースがあるより、いくつかの特定のインターフェースに分割すべき。 Before from abc import ABC, abstractmethod class Order: def __init__(self): self.items = [] self.quantities = [] self.prices = [] self.status = 'open' def add_item(self, name, quantity, price): self.items.append(name) self.quantities.append(quantity) self.prices.append(price) def total_price(self): total = 0 for i in range(len(self.prices)): total += self.quantities[i] * self.prices[i] return total class PaymentProcessor(ABC): @abstractmethod def auth_sms(self, code): pass @abstractmethod def pay(self, order): pass class DebitPaymentProcessor(PaymentProcessor): def __init__(self, security_code): self.security_code = security_code self.verified = False def auth_sms(self, code): print(f'Verifying SMS code {code}') self....

サブクラスは、スーパークラスと置換可能でなければならない。 Before from abc import ABC, abstractmethod class Order: def __init__(self) -> None: self.items = [] self.quantities = [] self.prices = [] self.status = 'open' def add_item(self, name: str, quantity: int, price: int) -> None: self.items.append(name) self.quantities.append(quantity) self.prices.append(price) def total_price(self) -> int: total = 0 for i in range(len(self.prices)): total += self.quantities[i] * self.prices[i] return total class PaymentProcessor(ABC): @abstractmethod def pay(self, order: Order, security_code: str) -> None: pass class DebitPaymentProcessor(PaymentProcessor): def pay(self, order: Order, security_code: str) -> None: print('Processing debit payment type') print(f'Verifying security code: {security_code}') order....

ソフトウェアの構成要素は拡張に対しては開いていて、修正に対しては閉じていなければならない。 ソフトウェアの振る舞いは、既存の成果物を変更せず拡張できるようにすべき。 Before class Order: def __init__(self) -> None: self.items = [] self.quantities = [] self.prices = [] self.status = "open" def add_item(self, name: str, quantity: int, price: int) -> None: self.items.append(name) self.quantities.append(quantity) self.prices.append(price) def total_price(self) -> int: total = 0 for i in range(len(self.prices)): total += self.quantities[i] * self.prices[i] return total class PaymentProcessor: def pay_debit(self, order: Order, security_code: str) -> None: print("Processing debit payment type") print(f"Verifying security code: {security_code}") order....

個々のモジュールを変更する理由がたったひとつだけになるように、ソフトウェアシステムの構造がそれを使う組織の社会的構造に大きな影響を受けるようにする。 モジュールはたったひとつのアクターに対して責務を負うべきである。 Before class Order: def __init__(self) -> None: self.items = [] self.quantities = [] self.prices = [] self.status = 'open' def add_item(self, name: str, quantity: int, price: int) -> None: self.items.append(name) self.quantities.append(quantity) self.prices.append(price) def total_price(self) -> int: total = 0 for i in range(len(self.prices)): total += self.quantities[i] * self.prices[i] return total def pay(self, payment_type: str, security_code: str) -> None: if payment_type == 'debit': print('Proccessing debit payment type') print(f'Verifying security code: {security_code}') self....