Jupyter Snippet CB2nd 09_hdf5_array

4.9. Manipulating large arrays with HDF5

import numpy as np
import h5py

f = h5py.File('myfile.h5', 'w')

f.create_group('/experiment1')

<HDF5 group "/experiment1" (0 members)>

f['/experiment1'].attrs['date'] = '2018-01-01'

x = np.random.rand(1000, 1000)
f['/experiment1'].create_dataset('array1', data=x)

<HDF5 dataset "array1": shape (1000, 1000), type "<f8">

f.close()

f = h5py.File('myfile.h5', 'r')

f['/experiment1'].attrs['date']

'2018-01-01'

y = f['/experiment1/array1']
type(y)

h5py._hl.dataset.Dataset

np.array_equal(x[0, :], y[0, :])

True

f.close()

import os
os.remove('myfile.h5')