How to use list as key of dictionary?

Boris Borcic bborcic at gmail.com
Tue Nov 6 11:41:18 CET 2007


You could also index on the repr() of your objects, which
is an immutable str value.

Davy wrote:
> And there may be more complex list(vector like 3 or 4 dimentional data
> structure), is there any easy method to tackle this problem?
> 
> Any suggestions are welcome!
> 
> Best regards,
> Davy
> 
> On Nov 6, 4:50 pm, Davy <zhushe... at gmail.com> wrote:
>> Hi Matimus and Boris,
>>
>> Thank you :)
>>
>> And a further question about vector above rank 1, how can I use it as
>> the key of dictionary?
>>
>> For example, if I have list like L=[[1,2,3],[4,5,6,7]],
>> Then I do L_tuple = tuple(L)>>> L_tuple = ([1,2,3],[4,5,6,7])
>>
>> But {L_tuple:'hello'} cause an error?
>>
>> Best regards,
>> Davy
>>
>> On Nov 6, 3:09 pm, Matimus <mccre... at gmail.com> wrote:
>>
>>
>>
>>> On Nov 5, 10:53 pm, Davy <zhushe... at gmail.com> wrote:
>>>> Hi all,
>>>> We know that list cannot be used as key of dictionary. So, how to work
>>>> around it?
>>>> For example, there is random list like l=[1,323,54,67].
>>>> Any suggestions are welcome!
>>>> Best regards,
>>>> Davy
>>> Use a tuple instead.
>>>>>> d = {}
>>>>>> d[tuple([1,2,3,4])] = 'hello world'
>>>>>> d
>>> {(1, 2, 3, 4): 'hello world'}>>> d[1,2,3,4]
>>> 'hello world'
>>> Matt- Hide quoted text -
>> - Show quoted text -
> 
> 



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