[IPython-User] ipython parallelism returning user-defined types
Fri Nov 12 11:51:24 CST 2010
On 10/11/10 21:39, Brian Granger wrote:
> > Hmm, that is an odd error that I have never seen. Even the fact
> that it is a
> > TypeError is odd to me. A couple of things to look at:
> > * Make sure that named tuples can be pickled and unpickled.
> namedtuple objects can be pickled, but you have to be particularly
> Creating a namedtuple type at the prompt and then trying to send
> that over won't
> work because the type won't be available on the other side.
> IPython's FakeModule
> will cause more complications. Creating a namedtuple type inside of
> a function
> is even worse since the pickle cannot address it by name. If you
> create the
> namedtuple type in a real module that is available to both
> interpreters, it will
> probably work.
> Robert makes good points. You do have to make sure types are in modules
> when using IPython. I would put namedtuple in a module, and then make
> sure you import that module in both the client and engine namespaces.
Yup, I think I had avoided these pitfalls but there was still the
TypeError. I imagine it is something to do with the recipe from the
activestate python cookbook. In any case the collections.namedtuple in
python 2.6 is working just fine.
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