[pypy-dev] Access the name of variable that is being assigned

[anatoly techtonik]

On Tue, Jul 15, 2014 at 12:50 PM, Yichao Yu <yyc1992 at gmail.com> wrote:
> On Tue, Jul 15, 2014 at 5:05 PM, anatoly techtonik <techtonik at gmail.com> wrote:
>> Hi,
>>
>> Is it possible at all to define a class in Python that
>> can read name of variable it is assigned to on init?
>>
>>   >>> MyObject = SomeClass()
>>   >>> print(MyObject)
>>   'MyObject'
>
> I thing in general a normal object in Python does not have a name and
> there's nothing special about the name of the variable it is assigned
> to first. To see why is is not going to work, what do you expect you
> print function to do if the object is created like
>
> some_function(SomeClass())

I don't need this case, so I can ignore it. But reliably detecting this to
distinguish from other situations would be nice.

> or
> some_other_object.some_attribute = SomeClass()

Detect that name is an attribute, handle distinctly if needed, for my
purpose print 'some_other_object.some_attribute'

> or
> some_variable = another_variable = SomeClass()

Print closest assigned variable name, i.e. 'another_variable'

> or
> some_variable = (SomeClass(),)

There is no direct assignment. Don't need this.

> or even
> SomeClass() # not assigning to anything
> etc....

Good to detect. Don't need. Actually all cases that I don't need are
the same case on this one - there is no direct assignment to variable.

> I guess it would be better if you can describe what you really want to do.

I described. Or you need use case or user story? I think I want to link
object instances to variable names without to print those names
(if possible) in __repr__ and debug messages to save time on
troubleshooting.