我目前有一些代码,例如:
class Bird:
pass
class Swallow(Bird):
__max_airspeed_velocity = 10
def __init__(self, laden):
self.laden = laden
@property
def max_velocity(self):
return self.__max_airspeed_velocity
@property
def current_velocity(self):
if self.laden:
return self.__max_airspeed_velocity / 2
else:
return self.__max_airspeed_velocity
class Parrot(Bird):
__max_in_cage_velocity = 8
def __init__(self, dead):
self.dead = dead
@property
def max_velocity(self):
return self.__max_in_cage_velocity
@property
def current_velocity(self):
if self.dead:
return 0
else:
return self.__max_in_cage_velocity
swallow = Swallow(True)
parrot = Parrot(False)
# Direct variable access is fine
swallow.__max_airspeed_velocity # 10
Swallow.__max_airspeed_velocity # 10
# Getter only works on instance. I see that it references "self", but it only looks at a class variable.
# In practice, this is an obvious reason why it doesn't work. But in theory there should still be a way?
swallow.max_velocity # 10
Swallow.max_velocity # Error
现在让我们说我想要一个比较鸟类的函数。我有时想问一下理论上的鸟类(班级),有时甚至是实际的鸟类(实例)。
def compare_max_velocity(bird1, bird2):
return bird1.max_velocity > bird2.max_velocity # only works on instances
compare_max_velocity(Swallow, Parrot) # can I do this using built-ins?
compare_max_velocity(swallow, parrot) # easy
我可以使用吸气剂编写此功能吗?我是否必须借助自己的get_max_velocity()函数(或直接变量访问)?