Optional parameter object re-used when instantiating multiple objects

[Steven D'Aprano]

Re: Optional parameter object re-used when instantiating multipleobjects

On Thu, 20 Nov 2008 04:42:24 -0800, Aaron Brady wrote:

On Nov 19, 7:58 pm, alex23 <wuwe...@gmail. comwrote:

>On Nov 20, 10:14 am, Aaron Brady <castiro...@gma il.comwrote:
>>

If you had a menu in a browser interface that had the items, say,
'Stop' and 'Reload', what would you expect to happen if you clicked
on them?

>>
>If you had a keyword called 'def', which defined functions, would you
>expect it to define said functions when it executed, or on each
>function call?

>
At first, I would expect it to define them at compile-time. Then, when
I learned there was no such thing,

Of course there is compile-time. When did you think the .pyc files got
created?

The same thing happens in the interactive interpreter: the function is
compiled to byte-code, and then the compiled function is executed by the
VM.



--
Steven

[alex23]

Re: Optional parameter object re-used when instantiating multipleobjects

On Nov 21, 10:07 am, Aaron Brady <castiro...@gma il.comwrote:

Why, I would expect the interpreter to define the functions when it
first hits the def, that is, at the point of definition.

Then why are you arguing that the parameters should be re-defined at
the point of calling?

[Chris Rebert]

Re: Optional parameter object re-used when instantiating multipleobjects

On Thu, Nov 20, 2008 at 9:26 PM, alex23 <wuwei23@gmail. comwrote:

On Nov 21, 10:07 am, Aaron Brady <castiro...@gma il.comwrote:

>Why, I would expect the interpreter to define the functions when it
>first hits the def, that is, at the point of definition.

>
Then why are you arguing that the parameters should be re-defined at
the point of calling?

I would assume because using the "def is start of definition" theory,
anything after the "def" is part of the function definition/body and
should not be immediately executed, but rather be executed at
call-time. The function body comes after the "def" and doesn't get run
immediately, so neither should the default argument values.

I take no position on the virtue of said theory.

Cheers,
Chris
--
Follow the path of the Iguana...

http://rebertia.com

>
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>

[Aaron Brady]

Re: Optional parameter object re-used when instantiating multipleobjects

On Nov 20, 11:26 pm, alex23 <wuwe...@gmail. comwrote:

On Nov 21, 10:07 am, Aaron Brady <castiro...@gma il.comwrote:
>

Why, I would expect the interpreter to define the functions when it
first hits the def, that is, at the point of definition.

>
Then why are you arguing that the parameters should be re-defined at
the point of calling?

Hmm. You have conflated defining the function with defining the
parameters.

My argument is that the syntax doesn't obviously imply either
interpretation.

I advocate a 'nonstatic' decorator. Also, I don't think a 'static'
decorator, had Python taken the other interpretation, would have been
that bad a combination.

[alex23]

Re: Optional parameter object re-used when instantiating multipleobjects

On Nov 21, 7:49 pm, Aaron Brady <castiro...@gma il.comwrote:

On Nov 20, 11:26 pm, alex23 <wuwe...@gmail. comwrote:
>

On Nov 21, 10:07 am, Aaron Brady <castiro...@gma il.comwrote:

>

Why, I would expect the interpreter to define the functions when it
first hits the def, that is, at the point of definition.

>

Then why are you arguing that the parameters should be re-defined at
the point of calling?

>
Hmm.  You have conflated defining the function with defining the
parameters.

No, I think I've made the mistake of joining yet another pointless
thread arguing about semantics.

[Aaron Brady]

Re: Optional parameter object re-used when instantiating multipleobjects

On Nov 21, 4:24 am, alex23 <wuwe...@gmail. comwrote:

On Nov 21, 7:49 pm, Aaron Brady <castiro...@gma il.comwrote:
>

On Nov 20, 11:26 pm, alex23 <wuwe...@gmail. comwrote:

>

On Nov 21, 10:07 am, Aaron Brady <castiro...@gma il.comwrote:

>

Why, I would expect the interpreter to define the functions when it
first hits the def, that is, at the point of definition.

>

Then why are you arguing that the parameters should be re-defined at
the point of calling?

>

Hmm.  You have conflated defining the function with defining the
parameters.

>
No, I think I've made the mistake of joining yet another pointless
thread arguing about semantics.

I was making the case that the options were about the same. Then you
had some questions.

I said, I would expect the interpreter to define the functions at a
certain time.

You asked, why are you arguing that the parameters should be re-
defined at a different time.

You assumed that defining a function and defining its parameters
necessarily happen at the same time. Not so.