Apparently .npz files have a limit of ~4GB, which can be a problem when dealing with large datasets ($$600^3$$), so how do I write binary files of this size?! Looks like I need to migrate to HDF5…lol; here’s an example for read/write similar to npz:

import h5py
a = np.random.rand(1000,1000)
f = h5py.File('/tmp/myfile.hdf5')
f['a'] = a # <-- Save
f.close()

now that will write the file, lets open it

import h5py
f = h5py.File('/tmp/myfile.hdf5')
b = f['a']
#b = b[()]
f.keys() #shows all values in the dataset
f.close()

but the odd thing is, you can’t directly access the data here by just ‘b’. Instead there is a ton of information attached like b.shape, b.dtype, etc etc, all found here. Instead, you simply have to use the command

b.value

and that will output the data of the file.