mparray.py 文件源码

def chain(mpas, astype=None):
    """Computes the tensor product of MPAs given in ``*args`` by adding more
    sites to the array.

    :param mpas: Iterable of MPAs in the order as they should appear in the
        chain
    :param astype: dtype of the returned MPA. If ``None``, use the type of the
        first MPA.
    :returns: MPA of length ``len(args[0]) + ... + len(args[-1])``

    .. todo:: Make this canonicalization aware
    .. todo:: Raise warning when casting complex to real dtype

    """
    mpas = iter(mpas)
    try:
        first = next(mpas)
    except StopIteration:
        raise ValueError('Argument `mpas` is an empty list')
    rest = (lt for mpa in mpas for lt in mpa.lt)
    if astype is None:
        astype = type(first)
    return astype(it.chain(first.lt, rest))