One way to get around this limitation in python is to use callable classes instead of functions. David
On Sat, Jun 14, 2008 at 10:42 AM, David Harvey <[EMAIL PROTECTED]> wrote: > > On Jun 14, 2008, at 1:25 PM, Daniel Bump wrote: > > > Some code that has been proposed by Nicolas Thiery > for sage/combinat/families.py would create classes > that have as attributes dictionaries of functions. > However dumps(s) will raise an exception if s is > such a class instance. > Example: the simple reflections in a Weyl group. See: > http://groups.google.com/group/sage-combinat-devel/msg/8b987cd471db3493?hl=en > What it boils down to is this. The following is > fine in native Python: > > import pickle > def f(x): return x+1 > > ... > > pickle.dumps(f) > > 'c__main__\nf\np0\n.' > > pickle.dumps({1:f}) > > '(dp0\nI1\nc__main__\nf\np1\ns.' > But if you try to run this from within Sage, > both calls to dumps() will raise exceptions. > Is this a bug in Sage? > > I actually thought you couldn't really pickle functions, even in plain > python. > http://docs.python.org/lib/node317.html > "Note that functions (built-in and user-defined) are pickled by ``fully > qualified'' name reference, not by value. This means that only the function > name is pickled, along with the name of module the function is defined in. > Neither the function's code, nor any of its function attributes are pickled. > Thus the defining module must be importable in the unpickling environment, > and the module must contain the named object, otherwise an exception will be > raised." > david > > > > --~--~---------~--~----~------------~-------~--~----~ To post to this group, send email to sage-devel@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/sage-devel URLs: http://www.sagemath.org -~----------~----~----~----~------~----~------~--~---
