Path: csiph.com!usenet.pasdenom.info!gegeweb.org!de-l.enfer-du-nord.net!feeder1.enfer-du-nord.net!newsfeed.kamp.net!newsfeed.kamp.net!newsfeed.freenet.ag!news2.euro.net!newsfeed.xs4all.nl!newsfeed5.news.xs4all.nl!xs4all!post.news.xs4all.nl!not-for-mail
Date: Wed, 12 Sep 2012 20:36:49 -0400
From: Dave Angel <d@davea.name>
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:14.0) Gecko/20120714 Thunderbird/14.0
MIME-Version: 1.0
To: Jabba Laci <jabba.laci@gmail.com>
Subject: Re: avoid the redefinition of a function
References: <CAOuJsMnLf4P9p_rZ4p1W-SndkSOV2WK_v5j1AET085LZ6bdavQ@mail.gmail.com> <5050938F.7030105@gmail.com> <CAOuJsMm6uANJNSRD=Qe70sBYWnnX55yF9dqxQTCcbx_nSfZGBg@mail.gmail.com>
In-Reply-To: <CAOuJsMm6uANJNSRD=Qe70sBYWnnX55yF9dqxQTCcbx_nSfZGBg@mail.gmail.com>
Content-Type: text/plain; charset=ISO-8859-1
Content-Transfer-Encoding: 7bit
Cc: Python mailing list <python-list@python.org>
Precedence: list
Reply-To: d@davea.name
Newsgroups: comp.lang.python
Message-ID: <mailman.585.1347496613.27098.python-list@python.org>
Lines: 47
NNTP-Posting-Host: 2001:888:2000:d::a6
Xref: csiph.com comp.lang.python:29006

On 09/12/2012 12:56 PM, Jabba Laci wrote:
> Thanks for the answers. I decided to use numbers in the name of the
> functions to facilitate function calls. Now if you have this menu
> option for instance:
>
> (5) install mc
>
> You can type just "5" as user input and step_5() is called
> automatically. If I use descriptive names like install_java() then
> selecting a menu point would be more difficult. And I don't want users
> to type "java", I want to stick to simple numbers.
>
> Laszlo

Many of the other answers were interesting and useful, but I don't think
anyone else pointed out the real problem with your code.

If you have a bunch of functions defined in one place, and a bunch of
choices for the user defined in another, you need to make one place
which maps them all together.  That way, when you define a new function,
you also define the part of the menu that tells the user what to type.

For example, you might make a list like the following:

CHOICES = [("install mc", install_mc),
                    ("install java", install_java),
                           ....etc....
                   ]

And your input routine will be something like:
           for  index, item in iterate(CHOICES):
                  print "(", index, ")", item[0]
           choice = int(raw_input())
           function = CHOICES[choice][1]

This isn't exactly the way i'd do it, and of course it's missing all
kinds of error checking.  But the point is that adding a new function to
the menu only requires one place to "know" the number of the function. 
And the number is only indirectly known, as the location in the CHOICES.

I hope this sparks some ideas.


-- 

DaveA