所以我有一个主班和几个辅助班。在主类的方法中,我将需要一些辅助对象,我想与这些辅助对象“共享”主实例的shared_data
属性,以便每当更改主对象的shared_data
属性时,辅助对象的对应对象属性也会相应地更新。 (具体来说,您可能会认为shared_data
为“时间”,我希望“时间”属性在各个对象之间保持同步)。
但是,似乎无法以下面的幼稚方式执行此操作,因为这实际上不会跨对象“共享”数据,而是仅将当前值分配给这些对象,因此这些对象属性将不会保留已同步。实现此“同步”或“共享”功能的正确方法应该是什么?
class Main:
def __init__(self, shared_data):
self.shared_data = shared_data
pass
def do_stuff(self):
# initialise auxiliary objects (only for once).
# hopefully when self.x1 is changed, the data in
# the objects aux1, aux2 will also reflect this change
aux1, aux2 = Aux1(self.shared_data), Aux2(self.shared_data)
# however, in general, changing self.shared_data would not
# change the data in aux1 or aux2
another_value = ...
self.shared_data = another_value # doesn't work
pass
class Aux1:
def __init__(self, x1):
self.x1 = x1
...
pass
class Aux2:
def __init__(self, x2):
self.x2 = x2
...
pass
除了这部分,一切都很好:
self.shared_data = another_value # doesn't work
该行不会修改shared_value
。它只是为持有共享数据对象之前的变量分配了一个不同的对象。
您需要做的是修改shared_value
,例如这样:
self.shared_value.data = another_data
这里是一个完整的例子:
class SharedData:
def __init__(self):
self.time = 0
self.colour = "red"
class ObjectWithSharedData:
def __init__(self, shared_data):
self._shared_data = shared_data
def do_stuff(self):
self._shared_data.time = 7
def get_time(self):
return self._shared_data.time
shared_data = SharedData()
a = ObjectWithSharedData(shared_data)
b = ObjectWithSharedData(shared_data)
c = ObjectWithSharedData(shared_data)
a.do_stuff()
print(a.get_time()) # prints 7
print(b.get_time()) # prints 7
print(c.get_time()) # prints 7