获取virtual_servers默认的pool

import sys
import pycontrol.pycontrol as pc
import time
import csv
import ssl
ssl._create_default_https_context = ssl._create_unverified_context
pool='YXPT_ust_pool'

b = pc.BIGIP(
hostname = '10.4.170.160',
username = 'zjtlcb',
password = 'xxx',
fromurl = True,
wsdls=['LocalLB.VirtualServer'])
pools = b.LocalLB.VirtualServer
print pools
print dir(pools)
aa=pools.get_list()
for x in aa:
a= pools.get_default_pool_name(virtual_servers=[x])
print x+'=>'+a[0]