human
Complete the below
def construct_source_candidate_set(addr, plen, laddr, loname):

    ''''Given all addresses assigned to a specific interface (\'laddr\' parameter),
    this function returns the "candidate set" associated with \'addr/plen\'.
    Basically, the function filters all interface addresses to keep only those
    that have the same scope as provided prefix.
    This is on this list of addresses that the source selection mechanism
    will then be performed to select the best source address associated
    with some specific destination that uses this prefix.'
    '''

Write me a the Python code you requested?
assistant
#Here is the Python code you requested.
    def cset_sort(x, y):
        x_global = 0
        if in6_isgladdr(x):
            x_global = 1
        y_global = 0
        if in6_isgladdr(y):
            y_global = 1
        res = (y_global - x_global)
        if ((res != 0) or (y_global != 1)):
            return res
        if (not in6_isaddr6to4(x)):
            return (-1)
        return (- res)
    cset = []
    if (in6_isgladdr(addr) or in6_isuladdr(addr)):
        cset = filter((lambda x: (x[1] == IPV6_ADDR_GLOBAL)), laddr)
    elif in6_islladdr(addr):
        cset = filter((lambda x: (x[1] == IPV6_ADDR_LINKLOCAL)), laddr)
    elif in6_issladdr(addr):
        cset = filter((lambda x: (x[1] == IPV6_ADDR_SITELOCAL)), laddr)
    elif in6_ismaddr(addr):
        if in6_ismnladdr(addr):
            cset = [('::1', 16, loname)]
        elif in6_ismgladdr(addr):
            cset = filter((lambda x: (x[1] == IPV6_ADDR_GLOBAL)), laddr)
        elif in6_ismlladdr(addr):
            cset = filter((lambda x: (x[1] == IPV6_ADDR_LINKLOCAL)), laddr)
        elif in6_ismsladdr(addr):
            cset = filter((lambda x: (x[1] == IPV6_ADDR_SITELOCAL)), laddr)
    elif ((addr == '::') and (plen == 0)):
        cset = filter((lambda x: (x[1] == IPV6_ADDR_GLOBAL)), laddr)
    cset = map((lambda x: x[0]), cset)
    cset.sort(cmp=cset_sort)
    return cset