| """Stok yönetimi: arayüz (sözleşme) testleri için örnek. |
| |
| Genel API: |
| Product(sku, name, price) -> değişmez veri sınıfı |
| Inventory.add(product, qty) -> int -> yeni stok miktarı |
| Inventory.remove(sku, qty) -> int -> KeyError (yok), ValueError (yetersiz/geçersiz) |
| Inventory.total_value() -> float |
| Inventory.low_stock(threshold) -> list[str] (sku listesi, sıralı) |
| """ |
| from dataclasses import dataclass, field |
| from typing import Dict |
|
|
|
|
| @dataclass(frozen=True) |
| class Product: |
| sku: str |
| name: str |
| price: float |
|
|
| def __post_init__(self): |
| if not self.sku: |
| raise ValueError("sku zorunlu") |
| if self.price < 0: |
| raise ValueError("fiyat negatif olamaz") |
|
|
|
|
| @dataclass |
| class Inventory: |
| _items: Dict[str, Product] = field(default_factory=dict) |
| _stock: Dict[str, int] = field(default_factory=dict) |
|
|
| def add(self, product: Product, qty: int = 1) -> int: |
| if qty <= 0: |
| raise ValueError("miktar pozitif olmalı") |
| existing = self._items.get(product.sku) |
| if existing is not None and existing != product: |
| raise ValueError("aynı sku farklı ürünle kullanılamaz") |
| self._items[product.sku] = product |
| self._stock[product.sku] = self._stock.get(product.sku, 0) + qty |
| return self._stock[product.sku] |
|
|
| def remove(self, sku: str, qty: int = 1) -> int: |
| if sku not in self._stock: |
| raise KeyError(sku) |
| if qty <= 0: |
| raise ValueError("miktar pozitif olmalı") |
| if self._stock[sku] < qty: |
| raise ValueError("yetersiz stok") |
| self._stock[sku] -= qty |
| if self._stock[sku] == 0: |
| del self._stock[sku] |
| del self._items[sku] |
| return 0 |
| return self._stock[sku] |
|
|
| def quantity(self, sku: str) -> int: |
| return self._stock.get(sku, 0) |
|
|
| def total_value(self) -> float: |
| return round(sum(self._items[s].price * q for s, q in self._stock.items()), 2) |
|
|
| def low_stock(self, threshold: int = 5) -> list: |
| return sorted(s for s, q in self._stock.items() if q < threshold) |
|
|
