keys in dictionary

[Shi Mu]

I run the following code and got wrong message, but I still want to
make [1,2],[4,3] and [6,9]
to be keys of the dictionary or change the style a little bit. How to do that?
Thanks!
[color=blue][color=green][color=darkred]
>>> p=[[1,2],[4,3],[6,9]]
>>> n=dict([(x,[]) for x in p])[/color][/color][/color]
Traceback (most recent call last):
File "<interacti ve input>", line 1, in ?
TypeError: list objects are unhashable[color=blue][color=green][color=darkred]
>>>[/color][/color][/color]

[Martin v. Löwis]

Re: keys in dictionary

Shi Mu wrote:[color=blue]
> I run the following code and got wrong message, but I still want to
> make [1,2],[4,3] and [6,9] to be keys of the dictionary or change the
> style a little bit. How to do that?[/color]

Make them tuples:
[color=blue][color=green][color=darkred]
>>> p=[[1,2],[4,3],[6,9]]
>>> n=dict([(tuple(x),[]) for x in p])
>>> n[/color][/color][/color]
{(6, 9): [], (1, 2): [], (4, 3): []}

Regards,
Martin

P.S. Please don't cross-post.

[Georges Barthelemy]

Re: keys in dictionary

use (1,2) , (3,4)....


"Shi Mu" <samrobertsmith @gmail.com> a écrit dans le message de news:
mailman.987.113 2638229.18701.p ython-list@python.org...
I run the following code and got wrong message, but I still want to
make [1,2],[4,3] and [6,9]
to be keys of the dictionary or change the style a little bit. How to do
that?
Thanks!
[color=blue][color=green][color=darkred]
>>> p=[[1,2],[4,3],[6,9]]
>>> n=dict([(x,[]) for x in p])[/color][/color][/color]
Traceback (most recent call last):
File "<interacti ve input>", line 1, in ?
TypeError: list objects are unhashable[color=blue][color=green][color=darkred]
>>>[/color][/color][/color]