np.load() fails to read empty archive created by np.savez()

[jzwinck]

Try this:

np.savez('nothing.npz') # OK
np.load('nothing.npz') # error

Loading fails:

OSError: Failed to interpret file 'nothing.npz' as a pickle

It should succeed (and give you an object with no arrays inside). Likewise for savez_compressed() (which also currently fails).

I'm using NumPy 1.13.1.

[ghost]

Implementation of _savez (which both savez andsavez_compressed use underneath) makes it possible to create empty archive, which load function cannot unpickle later:

_pickle.UnpicklingError: A load persistent id instruction was encountered,
but no persistent_load function was specified.

Can we add array as a required argument to savez and savez_compressed function calls?
Because currently only filename is required:

def savez(file, *args, **kwds):
    ...

def savez_compressed(file, *args, **kwds):
    ...

It will be also more compatible with save function:

def save(file, arr, allow_pickle=True, fix_imports=True):
    ...

[billmetangmo]

Hi . I am using Numpy 1.15.2 and still have this error. When do u think it will be available on a specific version ( not master branch) ?

Thanks

[mattip]

It is merged into master, so should automatically be in 1.16 when we branch it off master.