reference or pointer to some object?

Antoon Pardon apardon at
Thu Jan 13 04:42:51 EST 2005

Op 2005-01-12, Jeff Shannon schreef <jeff at>:
> Torsten Mohr wrote:
>> I still wonder why a concept like "references" was not
>> implemented in Python.  I think it is (even if small)
>> an overhead to wrap an object in a list or a dictionary.
> Because Python uses a fundamentally different concept for variable 
> names than C/C++/Java (and most other static languages).  In those 
> languages, variables can be passed by value or by reference; neither 
> term really applies in Python.  (Or, if you prefer, Python always 
> passes by value, but those values *are* references.)

I would think the reference was the id. As such python always
passes by reference, as the id of the parameter is the id
of the argument.

> Python doesn't 
> have lvalues that contain rvalues; Python has names that are bound to 
> objects.  Passing a parameter just binds a new name (in the called 
> function's namespace) to the same object.
> It's also rather less necessary to use references in Python than it is 
> in C et. al.

You use nothing but references in Python, that is the reason why
if you assign a mutable to a new name and modify the object through
either name, you see the change through both names.

Antoon Pardon

More information about the Python-list mailing list