how to get a class instance name during creation?

[dmitrey]

hi all,
I have a code
z = MyClass(some_args)
can I somehow get info in MyClass __init__ function that user uses "z"
as name of the variable?

I.e. to have __init__ function that creates field z.name with value
"z".

Thank you in advance, D.

[Gabriel Genellina]

En Fri, 03 Oct 2008 15:04:01 -0300, dmitrey <dm*************@scipy.org>
escribió:

I have a code
z = MyClass(some_args)
can I somehow get info in MyClass __init__ function that user uses "z"
as name of the variable?

I.e. to have __init__ function that creates field z.name with value
"z".

No. I'd just write it as:

z = MyClass(some, args, 'z')

wich is pretty simple and readable (although you have to repeat the 'z').
All the alternative ways I know of require too much black magic.

--
Gabriel Genellina

[Aaron \Castironpi\ Brady]

On Oct 3, 1:46*pm, Bruno Desthuilliers
<[e-mail]:

dmitrey a écrit :

hi all,
I have a code
z = MyClass(some_args)
can I somehow get info in MyClass __init__ function that user uses "z"
as name of the variable?

I.e. to have __init__ function that creates field z.name with value
"z".

This has been debated to hell and back. To make a long story short, here
are two common use cases:

x = MyClass()
y = x
del x

objects = [MyClass() for i in range(100)]

If you can come with a meaningfull answer to "what's *the* name of any
of the MyClass instance(s)" in both cases, then please let us know...

Hmmm, just thinking:

What about a function:

autoname( 'x= MyClass' )

which calls exec as well as determines the name? That could use
'code' and 'ast' modules and 'parse', or just take the first \w
characters, assuming assignment, or:

autoname( 'x', MyClass() )

which executes assignment and sets an attr or calls a method on the
second arg.

[dmitrey]

On Oct 3, 9:46*pm, Bruno Desthuilliers
<[e-mail]:

dmitrey a écrit :

hi all,
I have a code
z = MyClass(some_args)
can I somehow get info in MyClass __init__ function that user uses "z"
as name of the variable?

I.e. to have __init__ function that creates field z.name with value
"z".

This has been debated to hell and back. To make a long story short, here
are two common use cases:

x = MyClass()
y = x
del x

objects = [MyClass() for i in range(100)]

If you can come with a meaningfull answer to "what's *the* name of any
of the MyClass instance(s)" in both cases, then please let us know...

I had seen the examples during google search, still I hoped for an
answer to my exact situation. I know for sure there will be no
renaming and creating like the above objects = [MyClass() for i in
range(100)].
as for the z = MyClass(some, args, 'z') I had it in my mind but I
hoped to have something automatic, w/o the arg 'z'.
Regards, D.

[Ben Finney]

dmitrey <dm*************@scipy.orgwrites:

On Oct 3, 9:46Â*pm, Bruno Desthuilliers
<[e-mail]:

x = MyClass()
y = x
del x

objects = [MyClass() for i in range(100)]

If you can come with a meaningfull answer to "what's *the* name of
any of the MyClass instance(s)" in both cases, then please let us
know...

I had seen the examples during google search, still I hoped for an
answer to my exact situation. I know for sure there will be no
renaming and creating like the above objects = [MyClass() for i in
range(100)].

You *know* this, *for sure*? The only way I can think of that would
give you such certain knowledge that such a situation will not happen
is an automated, full-coverage unit test suite of all code that uses
your class. Which is an excellent position to be in, so I commend you
on your diligence.

So, why is it that you wish to restrict users of your class to never
do such normal operations with instances as in the above examples?
What problem are you solving by this restriction?

--
\ “Holy human pressure cookers, Batman!� —Robin |
`\ |
_o__) |
Ben Finney