对象继承和嵌套cmd
这可能是一个基本的面向对象问题: 我正在尝试使用 cmd 制作嵌套控制台菜单,效果很好。 我还希望所有子控制台都可以访问相同的对象。这进展并不顺利。
我的简单示例:
import cmd
class MainConsole(cmd.Cmd):
def __init__(self,obj1,obj2):
cmd.Cmd.__init__(self)
self.prompt = ">"
self.obj1 = obj1 # The objects I want access to in all my consoles.
self.obj2 = obj2
self.menu1 = SubConsole1() # I could pass in the objects here as arguments
self.menu2 = SubConsole2() # but there should be a better way.
def do_menu1(self,args):
self.menu1.cmdloop()
def do_menu2(self,args):
self.menu2.cmdloop()
def do_info(self,args):
self.menu1.do_info(args)
self.menu2.do_info(args)
def do_exit(self,args):
return -1
class SubConsole1(cmd.Cmd,MainConsole):
def __init__(self):
cmd.Cmd.__init__(self)
self.prompt = "1>"
def do_action(self,args):
print self.obj1.someattr1 # Doesn't work
class SubConsole2(cmd.Cmd,MainConsole):
def __init__(self):
cmd.Cmd.__init__(self)
self.prompt = "2>"
def do_action(self,args):
print obj1.someattr2 # Doesn't work
class anobject(object):
def __init__(self,init_value):
self.someattr1 = init_value
self.someattr2 = init_value * 2
object1 = anobject(1)
object2 = anobject(2)
c=MainConsole(object1,object2)
c.cmdloop()
当我运行此命令时,我会
>
>menu1
1>info
AttributeError: SubConsole1 instance has no attribute 'obj1'
再次尝试。
>
>menu2
2>info
NameError: global name 'obj1' is not defined
我不确定 SubConsole 是否应该是 MainConsole 的子类。我还尝试将 SubConsole 嵌套在 MainConsole
中。
This is probably a basic OO question:
I'm trying to do a nested console menu with cmd which has gone well.
I also want all my sub-consoles to have access to the same objects. This has not gone well.
My simple Example:
import cmd
class MainConsole(cmd.Cmd):
def __init__(self,obj1,obj2):
cmd.Cmd.__init__(self)
self.prompt = ">"
self.obj1 = obj1 # The objects I want access to in all my consoles.
self.obj2 = obj2
self.menu1 = SubConsole1() # I could pass in the objects here as arguments
self.menu2 = SubConsole2() # but there should be a better way.
def do_menu1(self,args):
self.menu1.cmdloop()
def do_menu2(self,args):
self.menu2.cmdloop()
def do_info(self,args):
self.menu1.do_info(args)
self.menu2.do_info(args)
def do_exit(self,args):
return -1
class SubConsole1(cmd.Cmd,MainConsole):
def __init__(self):
cmd.Cmd.__init__(self)
self.prompt = "1>"
def do_action(self,args):
print self.obj1.someattr1 # Doesn't work
class SubConsole2(cmd.Cmd,MainConsole):
def __init__(self):
cmd.Cmd.__init__(self)
self.prompt = "2>"
def do_action(self,args):
print obj1.someattr2 # Doesn't work
class anobject(object):
def __init__(self,init_value):
self.someattr1 = init_value
self.someattr2 = init_value * 2
object1 = anobject(1)
object2 = anobject(2)
c=MainConsole(object1,object2)
c.cmdloop()
When I run this I get
>
>menu1
1>info
AttributeError: SubConsole1 instance has no attribute 'obj1'
Try again.
>
>menu2
2>info
NameError: global name 'obj1' is not defined
I'm not sure if the SubConsoles should be sub-classes of MainConsole
. I also tried nesting the SubConsoles inside of MainConsole
.
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编辑好吧,我误解了你在做什么。
你是对的,SubConsole1和2不需要继承MainConsole。但它们应该有对主控制台的引用。
类似于:
然后您可以通过访问 self.maincon.obj1 和 self.maincon.obj2 来访问您想要的对象
另一种选择,可能是设计中更好的选择从角度来看,就是将要访问的所有对象拉出到 Context 容器对象中,并让所有各种
Cmd
对象维护自己对该 Context 容器的引用。像这样的事情:
希望我说得足够清楚。
EDIT Okay, I misunderstood what you're doing.
You are right, SubConsole1 and 2 do not need to inherit from MainConsole. But they should have a reference to the main console.
Something like:
Then you can access the objects you want by accessing
self.maincon.obj1
andself.maincon.obj2
The other option, and probably a better one from a design point of view, is to pull out all the objects you want to access into a Context container object, and have all the various
Cmd
objects maintain their own reference to that Context container.Something like this:
Hope I was clear enough.
您不需要多重继承,但需要将 obj1 和 obj2 赋予继承的对象,除非您为 obj1 和 obj2 赋予一些默认值。
实例化:
You don't need multiple inheritance, but you need to give obj1 and obj2 to the inherited objects, except if you give some default values to obj1 and obj2.
instanciated by :
另一个答案是正确的,因为您不应该使用多重继承,因为以下情况是正确的:
创建主类的一个方法来创建子命令,将它们的引用传递给子命令的
__init__函数。这样你的对象就可以更自然地生成它的子对象。
然后你可以通过访问 self.maincon.obj1 和 self.maincon.obj2 来访问你想要的对象,并通过运行 maincon.spawnsubconsole( ) 假设 maincon 是主控制台类的实例。
The other answer is correct insofar as you should not be using multiple inherritance, as the following is true:
It would also be wise to create a method of your main class wich creates subcmds, passing their reference to the subcmd's
__init__
function. This way you have your object spawn its children more naturally.Then you can access the objects you want by accessing
self.maincon.obj1
andself.maincon.obj2
and get the sub-cmd by runningmaincon.spawnsubconsole()
assuming maincon is an instance of the main console class.