Python eliminate duplicates of list with unhashabl

问题:

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Closed 7 years ago.

Possible Duplicate:
Python: removing duplicates from a list of lists

Say i have list

a=[1,2,1,2,1,3]

If all elements in a are hashable (like in that case), this would do the job:

list(set(a))

But, what if

a=[[1,2],[1,2],[1,3]]

?

回答1:

Python 2

>>> from itertools import groupby
>>> a = [[1,2],[1,2],[1,3]]
>>> [k for k,v in groupby(sorted(a))]
[[1, 2], [1, 3]]

Works also in Python 3 but with caveat that all elements must be orderable types.

回答2:

This set comprehension works for the List of Lists to produce a set of tuples:

>>> {(tuple(e)) for e in a}
set([(1, 2), (1, 3)])

Then use that to turn it into a list of lists again with no duplicates:

>>> [list(x) for x in {(tuple(e)) for e in a}]
[[1, 2], [1, 3]]