A question on modification of a list via a function invocation

[Steve D'Aprano]

On Mon, 4 Sep 2017 11:30 pm, Antoon Pardon wrote:

> Op 04-09-17 om 15:24 schreef Steve D'Aprano:
>> I accept that many people dislike, or do not understand, conceptual models
>> where objects can be in more than one location at once. For many people,
>> dropping into the implementation and talking about references is easier to
>> understand. But that doesn't make it essential.
>>
>> The semantics of Python is that we assign objects to names, not references to
>> objects to names. There's no "get reference" or "address of" operation in
>> Python. We write:
> 
> What does that mean assigning objects to names?

Would it help if I use the term "bind" instead?

All values in Python are objects. Assignment looks like this:

target = expression

and Python evaluates the expression on the right, producing an object, and then
binds it to the target in the left.

The target is often a simple name, like:

foo = 1


but if you want to be pedantic[1] the target can also be more complicated:

func(arg).foo[bar] = 1



The glossary unfortunately doesn't define either name binding or assignment:

https://docs.python.org/3/glossary.html


but the Language Reference describes name binding:

https://docs.python.org/3/reference/executionmodel.html#naming-and-binding


and Wikipedia has a good description of it:

https://en.wikipedia.org/wiki/Name_binding





[1] And why not, I would if I were in your position *wink*


-- 
Steve
“Cheer up,” they said, “things could be worse.” So I cheered up, and sure
enough, things got worse.