Finding the instance reference of an object

Joe Strout joe at strout.net
Fri Oct 31 04:07:03 CET 2008


On Oct 30, 2008, at 6:38 PM, greg wrote:

> The distinction isn't about parameter passing, though, it's
> about the semantics of *assignment*. Once you understand
> how assigment works in Python, all you need to know then
> is that parameters are passed by assigning the actual
> parameter to the formal parameter. All else follows from
> that.
>
> This holds for *all* languages that I know about, both
> static and dynamic.

Just to be complete, it only holds in "ByVal" mode (for languages that  
have both ByVal and ByRef modes, like VB.NET).  A call-by-value  
parameter pass is equivalent to an assignment to the formal parameter,  
as you say.  A call-by-reference parameter is not.

This is yet another simple way to see what type of parameter passing  
Python uses.

> Once you know how assignment works in
> the language concerned, then you know how parameter
> passing works as well. There is no need for new terms.

Agreed.

Best,
- Joe





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