Save / load scipy array,sparse csr_matrix

A csr_matrix has 3 data attributes that matter:

.data

,

.indices

,
and

.indptr

.
All are simple ndarrays, so

numpy.save

will
work on them. Save the three arrays with

numpy.save

or

numpy.savez

,
load them back with

numpy.load

,
and then recreate the sparse matrix object with:

new_csr = csr_matrix((data, indices, indptr), shape=(M, N))

def save_sparse_csr(filename,array):

np.savez(filename,data = array.data ,indices=array.indices,indptr =array.indptr, shape=array.shape )

def load_sparse_csr(npzfilename):

loader = np.load(npzfilename)

return csr_matrix(( loader['data'], loader['indices'], loader['indptr']),shape = loader['shape'])

def save_ids_array(filename,array):

np.savez(filename+'.ids',data = array)

def load_ids_array(npzfilename):

loader = np.load(npzfilename)

return loader['data']