how yse re.find all for find domain in python code example

Example 1: what is join use for in python

>>> sentence = ['this','is','a','sentence']
>>> '-'.join(sentence)
'this-is-a-sentence'

Example 2: how to find unique sublist in list in python

In [22]: lst = [[1,2,3],[1,2],[1,2,3],[2,3],[4,5],[2,3],[2,4],[4,2]]

In [23]: set(frozenset(item) for item in lst)
Out[23]: 
set([frozenset([2, 4]),
     frozenset([1, 2]),
     frozenset([2, 3]),
     frozenset([1, 2, 3]),
     frozenset([4, 5])])