The behavior of sockets depends on platform and implementation details of OS and libc. Binding to ('[::]', 888) does not work for me on Linux. It might work on other problems. The majority of functions and methods in the socket module are thin wrappers around low-level OS features. 

>>> import socket
>>> import sys
>>> sys.version
'3.8.3 (default, May 29 2020, 00:00:00) \n[GCC 10.1.1 20200507 (Red Hat 10.1.1-1)]'
>>> sys.platform
'linux'
>>> s = socket.socket(socket.AF_INET6)
>>> s.bind(('[::]', 888))
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
socket.gaierror: [Errno -2] Name or service not known