Accessing parent objects

[D'Arcy Cain]

On 03/25/2018 04:37 AM, Jugurtha Hadjar wrote:
> On 03/24/2018 07:14 PM, D'Arcy Cain wrote:
>> class C1(dict):
>>    class C2(object):
>>      def f(self):
>>        return X['field']
>>
>> O1 = C1()
>> O1['field'] = 1
>> O2 = O1.C2()
>> print(O2.f())
> 
> I prefer to *feed* the child to the parent or vice versa. Simplifies
> things like testing.

That was my original solution but it seems clumsy.

O2 = O1.C2(O1)

IOW passing the parent object to the child class.  It just seems like
there should be some way to access the parent object in C2.

> Something like this:
> 
> class C1(object):
...
> class C2(object):
>     def __init__(self, parent=None):
>         self.parent = parent

Perhaps your email client is collapsing leading spaces but that isn't
what I wrote.  The C2 class is supposed to be a member of C1.  That's
why I called it as O1.C2() instead of just C2().  I was hoping that by
doing so that the data in O1 would somehow be available without having
to explicitly pass it as an argument.

However, I would have made the parameter required.  I don't see the
point of calling another method to add it in later.  Of course, if I do
that there's no point in making C2 part of C1.  What you wrote would be
just fine and obvious.

-- 
D'Arcy J.M. Cain
Vybe Networks Inc.
http://www.VybeNetworks.com/
IM:darcy at Vex.Net VoIP: sip:darcy at VybeNetworks.com