def hstack(blocks, format=None, dtype=None):

    blocks = [as_sparse_variable(i) for i in blocks]
    if dtype is None:
        dtype = theano.scalar.upcast(*[i.dtype for i in blocks])
    return HStack(format=format, dtype=dtype)(*blocks)
Stack sparse matrices horizontally (column wise).
dataset/ETHPy150Open rizar/attention-lvcsr/libs/Theano/theano/sparse/basic.py/hstack