企业客服系统年末特惠

class InventoryManager:
    def __init__(self):
        self.inventory = {}

    def add_product(self, product_id, quantity):
        if product_id in self.inventory:
            self.inventory[product_id] += quantity
        else:
            self.inventory[product_id] = quantity

    def update_inventory(self, product_id, quantity):
        if product_id in self.inventory:
            self.inventory[product_id] = quantity
        else:
            raise ValueError("Product not found in inventory")

    def check_availability(self, product_id, quantity):
        if product_id in self.inventory and self.inventory[product_id] >= quantity:
            return True
        return False

# 使用示例
inventory_manager = InventoryManager()
inventory_manager.add_product('P123', 100)
print(inventory_manager.check_availability('P123', 50))  # 输出: True
inventory_manager.update_inventory('P123', 30)
print(inventory_manager.check_availability('P123', 50))  # 输出: False