scipy.sparse.csr_matrix.

tobsr

csr_matrix.tobsr(blocksize=None, copy=True)

Convert this array/matrix to Block Sparse Row format.

With copy=False, the data/indices may be shared between this array/matrix and the resultant bsr_array/matrix.

When blocksize=(R, C) is provided, it will be used for construction of the bsr_array/matrix.