[Python-ideas] Add 'use warnings' directive, like in Perl

[Ian Cordasco]

On Tue, Feb 10, 2015 at 1:53 PM, Eduard Bondarenko <eduardbpy at gmail.com> wrote:
> Well, Perl also dynamic language, but except the usage of the additional
> analyser tools he provides 'use warning' directive and many Perl's
> developers use this feature.

First of all, Python is not a "he". Python is an "it".

> Why you do not want to add such feature in Python ?
>
> If developer do not want to use this feature and want to use static analyser
> tools - okay. But what if someone wants to checks errata (not even an
> errors) without the s.a tools ?

You don't seem to understand that this functionality already exists.
Perl added it in the beginning because dependencies were the
antithesis of the Perl development ideology. Dependencies and tooling
are encouraged and accepted in the Python community meaning that the
interpreter itself doesn't need to be responsible for every possible
function a developer could possibly ever desire.

> To my mind some people simply do not know that even dynamic language can do
> some checks..

Except we use a dynamic language to build the checks that we have...
so we clearly already know this.

> I am, as a developer which came from Perl programming language really do not
> understand how you can agree with this behaviour and why you are really do
> not understand me..

We understand you. Some of us have come from the Perl community as
well. It doesn't mean we don't appreciate "use warnings;" when writing
Perl, it means we as a community understand that this doesn't belong
in the Python interpreter.

> Where it is written that dynamic language should not checks such things ?

It isn't. But perl doesn't do it by default either. It's "good style"
for a developer to turn that on, but it isn't required and perl (as a
dynamic language) clearly things it shouldn't be checking those things
without a user asking it too. That same philosophy is at work here.
Python doesn't check these things unless you use tools to check them
for you. "use warnings" is a tool, it just isn't a tool you install
separately.

> Seems very strange that Python checks ordinary blocks like 'if', 'else',
> 'def' statement and others..We could just have a big amount of tools to
> check this.

So now you're arguing for Python to stop checking the Syntax of the
program for errors? I'm confused.

> I do not want to create C++ from Python. I just want to correct this
> situation, when you can not say to interpreter "please check at least
> something!!"

It does check something. It checks that you use valid syntax. It
checks that it can import the code you use in your code. Depending on
what else happens, it checks numerous other things too. So it's doing
exactly what you want, it's checking more than one thing, and you
asked for at least one, so your request is satisfied.

> Many thanks!
>
> - Eduard
>
>
> 2015-02-10 20:55 GMT+02:00 Chris Barker <chris.barker at noaa.gov>:
>>
>> On Tue, Feb 10, 2015 at 10:51 AM, Skip Montanaro
>> <skip.montanaro at gmail.com> wrote:
>>>
>>>
>>> On Tue, Feb 10, 2015 at 12:07 PM, Chris Barker <chris.barker at noaa.gov>
>>> wrote:
>>>>
>>>> ... simply not known at run-time.
>>>
>>>
>>> Do you mean "simply not known until run-time"?
>>
>>
>> indeed -- the stuff we don't even know at run time is a whole different
>> matter ;-)
>>
>> -Chris
>>
>>
>>
>>>
>>> Cheers,
>>>
>>> Skip
>>>
>>>
>>
>>
>>
>> --
>>
>> Christopher Barker, Ph.D.
>> Oceanographer
>>
>> Emergency Response Division
>> NOAA/NOS/OR&R            (206) 526-6959   voice
>> 7600 Sand Point Way NE   (206) 526-6329   fax
>> Seattle, WA  98115       (206) 526-6317   main reception
>>
>> Chris.Barker at noaa.gov
>
>
>
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