更新时间:2023-01-08 08:12:25
var1
和 var2
是 实例变量.这意味着您必须将 ClassA
的实例发送到 ClassB
以便 ClassB 访问它,即:
var1
and var2
are instance variables. That means that you have to send the instance of ClassA
to ClassB
in order for ClassB to access it, i.e:
class ClassA(object):
def __init__(self):
self.var1 = 1
self.var2 = 2
def methodA(self):
self.var1 = self.var1 + self.var2
return self.var1
class ClassB(ClassA):
def __init__(self, class_a):
self.var1 = class_a.var1
self.var2 = class_a.var2
object1 = ClassA()
sum = object1.methodA()
object2 = ClassB(object1)
print sum
另一方面 - 如果您要使用类变量,您可以访问 var1 和 var2,而无需将 object1 作为参数发送给 ClassB.
On the other hand - if you were to use class variables, you could access var1 and var2 without sending object1 as a parameter to ClassB.
class ClassA(object):
var1 = 0
var2 = 0
def __init__(self):
ClassA.var1 = 1
ClassA.var2 = 2
def methodA(self):
ClassA.var1 = ClassA.var1 + ClassA.var2
return ClassA.var1
class ClassB(ClassA):
def __init__(self):
print ClassA.var1
print ClassA.var2
object1 = ClassA()
sum = object1.methodA()
object2 = ClassB()
print sum
但是请注意,类变量在其类的所有实例之间共享.
Note, however, that class variables are shared among all instances of its class.