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

[Eduard Bondarenko]

Hello Dennis,

I know that, actually I mean the simple version of Perl's 'use warnings'
directive. I do not mean to show warnings like " "isn't numeric" " in the
code below or something like this.

my $a = "2:" + 3;

And roughly speaking, I mentioned Perl's directive to more clearly show
what I mean.

About your reference.
If I correctly understood provided material this is runtime warnings and
absolutely not the same what I mean.

2015-02-11 11:03 GMT+02:00 Dennis Kaarsemaker <dennis at kaarsemaker.net>:

> Hi Eduard,
>
> What you describe is not at all equivalent to 'use warnings' in perl.
> 'use warnings' is a directive to enable/disable all or certain warnings
> perl code may emit. The equivalent of this exists in python:
>
> https://docs.python.org/3.1/library/warnings.html
>
> On di, 2015-02-10 at 18:04 +0200, Eduard Bondarenko wrote:
> > Hello group,
> >
> > my name is Eduard. I came into the Python community with an idea to
> > add (implicitly or explicitly) 'use warnings' directive into the
> > python's programs.
> >
> > I think that everyone who worked with Perl understand what I am
> > talking about. For the rest I will explain the idea.
> >
> > Actually, this is my first experience for writing into the community
> > like this, so excuse me if you found some mistakes or oddities. Also I
> > do not know whether you are already talk about this topic..in any case
> > - sorry.
> >
> > So, imagine that you have a program:
> >
> > #!/usr/bin/python
> >
> > word = raw_input("Enter line : ")
> >
> > if word == "hello":
> >   print ("You wrote \'hello\'")
> > else:
> >   if world == "buy": #Error! should be word not world
> >     print "Buy"
> > else:
> >   iamnotfunction #Also error
> >
> > This script contains two errors. And in both cases we will know about
> > it at runtime. And the most worst thing is that you will not know
> > about these errors until someone enters anything other than the
> > "hello" word..
> >
> > Try and except blocks do not solve this problem. Within this approach
> > we also receive problem at runtime.
> >
> > What I propose ? I propose to add 'use warnings' directive. This
> > directive will provide deeply verification. Like this:
> >
> > #!/usr/bin/python
> >
> > use warnings
> >
> > word = raw_input("Enter line : ")
> >
> > if word == "hello":
> >   print ("You wrote \'hello\'")
> > else:
> >   if world == "buy": #Error! should be word not world
> >     print "Buy"
> > else:
> >   iamnotfunction #Also error
> >
> > Output:
> > Use of uninitialized value world in  eq (==) at test.py line ..
> > Useless use of a constant (iamnotfunction) in void context at test.py
> > line ..
> >
> > The user will see the output like this and the program will not start.
> >
> >
> > To my mind the good idea is to explicitly set this directive. If
> > developer does not want spend time for this checking, he can omit 'use
> > warning' directive. Also it will not corrupt the existing programs.
> > And developers will have a chance to add this line gradually.
> >
> >
> >
> > Many thanks!
> >
> >
> > - Eduard
> >
> > _______________________________________________
> > Python-ideas mailing list
> > Python-ideas at python.org
> > https://mail.python.org/mailman/listinfo/python-ideas
> > Code of Conduct: http://python.org/psf/codeofconduct/
>
> --
> Dennis Kaarsemaker
> http://www.kaarsemaker.net
>
>
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