How to copy an instance without its cStringIO.StringO item ?

[Christian Heimes]

Barak, Ron schrieb:
> Hi,
> 
> I need to copy an instance of a class, where one of the items in the original is a cStringIO.StringO object.
> I do not need the cStringIO.StringO in the target object.
> The target instance is to be pickled.
> 
> Googling made me devise the following plan: do a deepcopy from the original to the target, and then delete the cStringIO.StringO object from the target.
> 
> However, trying to use copy.deepcopy produced: TypeError: object.__new__(cStringIO.StringO) is not safe, use cStringIO.StringO.__new__()
> 
> Is there a way to create a copy of the instance, sans the cStringIO.StringO ?
> 
> If I find no elegant way to do that, I thought of creating a "blank" target instance; then iterating over the __dict__ of the original, and manually copy the items to the target (while not copying the cStringIO.StringO to the target).
> 
> Can you suggest a better way ?

You can overwrite some functions in order to omit attributes from a
pickle. It's all documented at
http://docs.python.org/library/pickle.html#pickling-and-unpickling-normal-class-instances

Christian