[pypy-dev] improve error message when missing 'self' in method definition

[Maciej Fijalkowski]

On Tue, Sep 27, 2016 at 8:33 PM, Ryan Gonzalez <rymg19 at gmail.com> wrote:
> Have you considered bringing this up on python-ideas, too?

python-idea is generally quite a hostile place. That said, if you
think it's worth your effort to submit it there, feel free to do so,
just the core pypy devs feel their time is better spent elsewhere than
arguing on python-ideas

>
> On Tue, Sep 27, 2016 at 12:19 PM, Carl Friedrich Bolz <cfbolz at gmx.de> wrote:
>>
>> Hi all,
>>
>> I read this paper today about common mistakes that Python beginners
>> make:
>>
>>
>> https://www.researchgate.net/publication/307088989_Some_Trouble_with_Transparency_An_Analysis_of_Student_Errors_with_Object-oriented_Python
>>
>> The most common one by far is forgetting the "self" parameter in the
>> method definition (which also still happens to me regularly). The error
>> message is not particularly enlightening, if you don't quite understand
>> the explicit self in Python.
>>
>>
>> So I wonder whether we should print a better error message, something
>> like this:
>>
>> $ cat m.py
>> class A(object):
>>     def f(x):
>>         return self.x
>> A().f(1)
>>
>> $ pypy m.py
>> Traceback (application-level):
>>   File "m.py", line 4 in <module>
>>     A().f(1)
>> TypeError: f() takes exactly 1 argument (2 given). Did you forget 'self'
>> in the function definition?
>>
>>
>> It's a bit the question how clever we would like this to be to reduce
>> false positives, see the attached patch for a very simple approach.
>>
>> Anyone have opinions?
>>
>> Cheers,
>>
>> Carl Friedrich
>>
>> _______________________________________________
>> pypy-dev mailing list
>> pypy-dev at python.org
>> https://mail.python.org/mailman/listinfo/pypy-dev
>>
>
>
>
> --
> Ryan
> [ERROR]: Your autotools build scripts are 200 lines longer than your
> program. Something’s wrong.
> http://kirbyfan64.github.io/
>
>
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