Unpickling from strings

[Fredrik Lundh]

Marcin Chady wrote:
> I have pickled an object into a string and saved it in an hidden HTML form
> field, so that I can recover the state when the form is resubmitted.
> However, when the form comes back and I try to unpickle my object I get an
> error saying that the module in which the object's class was originally
> defined is unknown, even though the CGI script which does the unpickling has
> already imported the module!
>
> Has anyone got an idea why it is?

did you pickle classes defined in your main script (aka __main__),
and then failed to unpickle them in another script?

don't do that.

(to solve this, move the classes to a common support module, and
import it into the pickling script)

Cheers /F