A question on modification of a list via a function invocation

[Steven D'Aprano]

On Tue, 05 Sep 2017 21:17:30 -0700, Rustom Mody wrote:

> Sure you can say with Steven that this can be 'explained' by saying an
> object can be in two places at one time.
> Others would then say 'Humpty-dumpty!' since you have removed the most
> basic intuition of objects and you are in effect saying that a python
> object means what you ordain it means without further ado/explanation

I have previously agreed that the "multiple places at once" metaphor is 
not to everyone's liking.

But many (perhaps even most) people have no problem dealing with location 
as a metaphor, where being in two places (metaphorically) is no problem 
at all:

- I am in love, in trouble and in denial all at once.

Even when the location is not a state of being but an actual physical 
place, we can be in multiple places at once:

- I am in my home, in Melbourne, and in Australia all at once.

Being in two places at once is a common trope in both fantasy and science 
fiction (often involving time travel). These are not niche genres: they 
are *extremely* popular. One of the Harry Potter movies involved Harry, 
Ron and Hermoine travelling backwards in time a few minutes to watch 
themselves. It's a moderately common trope in stories like Doctor Who, 
where the Doctor frequently interacts with his past (or future) self. I 
recently saw an episode of Dark Matter that used the trope.

Robert Heinlein, one of the greats of SF, wrote a number of classic time 
travel stories involving people being in multiple places at once. (In one 
of them, the protagonist has a sex change and becomes *both* his own 
grandfather and grandmother.)

An object being inside itself is rarer, but its been done at least twice 
that I know of in Doctor Who.

Don't underestimate people's ability to stretch the location metaphor 
beyond actual physical location. We do it all the time for virtual 
locations like IRC channels:

- I'm in #python, #ruby and #javascript all at once.

But if the metaphor isn't for you, I'm not saying you have to use it.



-- 
Steven D'Aprano
“You are deluded if you think software engineers who can't write 
operating systems or applications without security holes, can write 
virtualization layers without security holes.” —Theo de Raadt