Error with: pickle.dumps(numpy.float32)

[Iljya]

Thanks, Ziga

I have submitted the bug to http://projects.scipy.org/scipy/numpy

I am using the following workaround for now:

>>> import numpy
>>> import pickle
>>> import __builtin__
>>> __builtin__.float32_arrtype = numpy.float32
>>> pickle.dumps(numpy.float32)
'c__builtin__\nfloat32_arrtype\np0\n.'

The name binding must also be present when unpickling.

Iljya Kalai

Ziga Seilnacht wrote:
> Iljya wrote:
> > I have reproduced the error with Numpy 1.0b1
> >
> > The output with v.1.0b1 reads:
> > PicklingError: Can't pickle <type 'float32scalar'>: it's not found as
> > __builtin__.float32scalar
> >
> > Has anyone else encountered this?
> >
> > Thanks,
> >
> > Iljya
> >
> > Iljya wrote:
> > > Hello,
> > >
> > > I need to pickle the type numpy.float32 but encounter an error when I
> > > try to do so. I am able to pickle the array itself, it is specifically
> > > the type that I cannot pickle.
> > >
> > > I am using:
> > > Numpy version: 0.9.4
> > > Python version: 2.4.3
> > > Windows XP
> > >
> > > Here is the code that reproduces the error:
> > > ______________________________________
> > > import numpy
> > > import pickle
> > >
> > > pickle.dumps(numpy.float32)
> > >
> > > Output:
> > > PicklingError: Can't pickle <type 'float32_arrtype'>: it's not found as
> > > __builtin__.float32_arrtype
> > > ______________________________________
> > >
> > > Any suggestions would be much appreciated.
> > >
> > > Thanks,
> > >
> > > Iljya Kalai
>
> This looks like a numpy bug. It seems that float32_arrtype's name is
> incomplete. Its tp_name field should start with a module name, but
> since it doesn't, Python assumes that it is a builtin type:
>
> >>> import numpy
> >>> numpy.float32.__module__
> '__builtin__'
>
> You should report this bug either to the numpy list:
> https://lists.sourceforge.net/lists/listinfo/numpy-discussion
>
> or to their bug tracker:
> http://projects.scipy.org/scipy/numpy
> 
> Ziga