UnboundLocalError: local variable '_[1]' referenced before assignment

[Bruno Desthuilliers]

Richard Thomas a écrit :
> On Dec 9, 10:17 am, Gabriel Rossetti <gabriel.rosse... at arimaz.com>
> wrote:
>>
>> UnboundLocalError: local variable '_[1]' referenced before assignment
>>
> 
> That isn't an error that should occur, not least because _[1] isn't a
> valid name

It's an internal identifier used in list comps. Implementation detail, 
really, you're not even supposed to know about it...