$ python3
>>>from netaddr import *
>>>from pprint import *
>>>a = IPRange("2620:E7:4000::","2620:E7:4000:FFFF:FFFF:FFFF:FFFF:FFFF")
>>>pprint(a)
IPRange('2620:e7:4000::', '2620:e7:4000:ffff:ffff:ffff:ffff:ffff')
>>>pprint(a.cidrs())
[IPNetwork('2620:e7:4000::/48')]