This is documentation for an old release of NumPy (version 1.6.0). Read this page in the documentation of the latest stable release (version > 1.17).
Total bytes consumed by the elements of the array.
Notes
Does not include memory consumed by non-element attributes of the array object.
Examples
>>> x = np.zeros((3,5,2), dtype=np.complex128)
>>> x.nbytes
480
>>> np.prod(x.shape) * x.itemsize
480