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Re: avoid the redefinition of a function

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  Re: avoid the redefinition of a function Dave Angel <d@davea.name> - 2012-09-12 20:36 -0400

#29006 — Re: avoid the redefinition of a function

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

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