python 括号匹配，多个括号并列排要加(?:)
pattern = re.compile(r'((?:[0-9a-f]{1,4})(?:\:[0-9a-f]{1,4}){1,7})')
pattern = re.compile(r'(([0-9a-f]{1,4})(\:[0-9a-f]{1,4}){1,7})')
line = "include = 2001:b8:1:2:20b:82ff:fe67:4bf"
match = pattern.findall(line)
print match
第一个pattern返回
['2001:b8:1:2:20b:82ff:fe67:4bf']
第二个pattern返回
[('2001:b8:1:2:20b:82ff:fe67:4bf', '2001', ':4bf')]