设计一个建筑物基类Building，由它派生出宿舍类Hostel和教学楼类Classroom，前者包括楼名、总层数、住户数、总住人数和总面积，后者包括楼名、总层数、教室数、灭火器数和总面积。

下面是基类Building的实现：

class Building:
    def __init__(self, name, floors, area):
        self.name = name
        self.floors = floors
        self.area = area

宿舍类Hostel和教学楼类Classroom则分别继承于基类Building，实现各自的特定属性和方法：

class Hostel(Building):
    def __init__(self, name, floors, area, rooms, beds_per_room):
        super().__init__(name, floors, area)
        self.rooms = rooms
        self.beds_per_room = beds_per_room
        self.occupants = 0
    
    def total_beds(self):
        return self.rooms * self.beds_per_room
    
    def add_occupants(self, occupants):
        self.occupants += occupants
    
    def total_occupants(self):
        return self.occupants
    
class Classroom(Building):
    def __init__(self, name, floors, area, classrooms, fire_extinguishers):
        super().__init__(name, floors, area)
        self.classrooms = classrooms
        self.fire_extinguishers = fire_extinguishers
    
    def total_fire_extinguishers(self):
        return self.classrooms * self.fire_extinguishers

使用示例：

h1 = Hostel("Building A", 5, 1000, 50, 4)
h1.add_occupants(150)
print(h1.total_beds()) # 200
print(h1.total_occupants()) # 150

c1 = Classroom("Building B", 3, 500, 10, 2)
print(c1.total_fire_extinguishers()) # 20