[IPython-User] IPython TaskClient map(): UnpickleableError???

[Frank Horowitz]

Hi All,

(A repost, as my earlier attempt did not seem to make it through.)

I'm trying to jam some moderately complicated data structures down the wire to the collection of engines, but am seeing the following error crop up:

UnpickleableError: Cannot pickle <type 'str'> objects

This is in response to a TaskClient instance's map() being called on a function with a single (tuple) argument where the sequence is being fed from a list.

I've done the obvious, and tried pickle and cPickle directly on strings, and those *do* work --- much as you'd expect. I suspect this is something within the guts of Twisted...

Any clues as to what might be causing this and/or how to avoid it? 

TIA for any help you might be able to provide!

Cheers,

	Frank Horowitz