P.start() return something like this :
'DateTime': '07, Mar 2018 10:45'}, {'Addr': '10.38.139.11', 'DateTime': '07, Mar 2018 10:45'}, {'
Addr': '10.38.139.23', 'DateTime': '07, Mar 2018 10:45'}, {'Addr': '10.38.139.12', 'DateTime': '07,
Mar 2018 10:45'}, {'Addr': '10.38.139.16', 'DateTime': '07, Mar 2018 10:45'}, {'Addr': '10.38.139
.14', 'DateTime': '07, Mar 2018 10:45'}], 'Length': 7}```
so, you can convert it to JSON
time0 = datetime.datetime.now()
ip_range = range(1,25)
ip_address_list = [ '10.28.136.{}'.format(x) for x in ip_range]
P = Ping(ip_address_list, 0.04)
dsting = json.dumps(P.start())
lstring = json.loads(dsting)
print(lstring['Available'][5]['Addr'])
print(lstring['Available'][5]['DateTime'])
time1 = datetime.datetime.now() - time0
print('exited with time {} \n'.format(time1))