How to pickle a subclass of tuple?

[Shalabh Chaturvedi]

Christos TZOTZIOY Georgiou wrote:

> __getstate__ is easy:
> 
> def __getstate__(self):
>     return tuple(self)
> 
> but even
> 
> def __getstate__(self):
>     return self
> 
> seems to work, as far as Pickle.dump is concerned.  The problem is, how
> one writes a __setstate__ for an immutable class?

Why do you need to do this i.e. redefine __getstate__() and __setstate__()?

Doesn't just pickling instances of your class work?

 >>> class T(tuple):pass
...
 >>> t = T((1,2))
 >>> t.a = 33
 >>> import pickle
 >>> x = pickle.loads(pickle.dumps(t))
 >>> x
(1, 2)
 >>> x.a
33
 >>>

--
Shalabh