Method default argument whose type is the class not yet defined

Mark Lawrence breamoreboy at yahoo.co.uk
Mon Nov 12 02:35:04 CET 2012


On 12/11/2012 01:15, Roy Smith wrote:
> In article <mailman.3570.1352682390.27098.python-list at python.org>,
>   Mark Lawrence <breamoreboy at yahoo.co.uk> wrote:
>
>> On 12/11/2012 00:31, Oscar Benjamin wrote:
>>>
>>> Plain wrong. Vectors are not defined *from any origin*.
>>>
>>
>> So when the Captain says "full speed ahead, steer 245 degrees", you
>> haven't the faintest idea where you're going, because you have no origin?
>
> Vectors have a length ("full speed ahead") and a direction ("245
> degrees").  What they don't have is a fixed location in space.  The
> captain didn't say, "Full speed ahead, steer 245 degrees, from 45.0N,
> 20.0W".
>
> In other words, you are correct.  The order, "full speed ahead, steer
> 245 degrees", doesn't give you the faintest idea of where you're going.
> If you were the helmsman, after you executed that order, without any
> additional information (such as your current location), you would have
> no idea what piece of land you will hit, or when you will hit it, if you
> maintain your current course and speed.
>

Thank you for your explanation.

-- 
Cheers.

Mark Lawrence.



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