shelve.open call gives error

[waltbrad]

On Feb 8, 5:29 pm, "Gabriel Genellina" <gagsl-... at yahoo.com.ar> wrote:
> En Fri, 08 Feb 2008 06:36:53 -0200, waltbrad <waltb... at hotmail.com>
> escribió:
>
>
>
> > Working through the Mark Lutz book Programming Python 3rd Edition.
>
> > A couple of modules in the "Preview" chapter give me errors. Both on a
> > shelve.open call:
>
> > Pretty simple code, (2nd example):
> > =====code begin=====
> > import shelve
> > from people import Person, Manager
>
> > bob = Person('Bob Smith', 42, 30000, 'sweng')
> > sue = Person('Sue Jones', 45, 40000, 'music')
> > tom = Manager('Tom Doe', 50, 50000)
>
> > db = shelve.open('class-shelve')
> > db['bob'] = bob
> > db['sue'] = sue
> > db['tom'] = tom
> > db.close()
> > ====code end====
>
> shelve uses the anydbm module; anydbm tries to select the best database
> module available, but apparently fails in your system. If you are just
> learning Python, I don't think it's worth trying to fix it; instead, let's
> force anydbm to use the fallback module dumbdbm (implemented in pure
> python, slow, but bullet-proof, or at least arrow-proof :) )
>
> Add these two lines at the start of your script:
>
> import dumbdbm, anydbm
> anydbm._defaultmod = dumbdbm
>
> Remove the class-shelve.* files, if any, before running it.
>
> --
> Gabriel Genellina

Thanks to all for the help, but the only advice that worked was
Gabriel's.

I actually tried to look into the issue of fixing it, but I'm just too
much of a novice.

I put the two lines in a seperate module that I import to save typing.

But as I gain experience I'd like to return to this issue and try to
fix it.  Can you give me advice on how to go about that?

I'm working on a win98 system.  I have python on a linux system,
(Kubuntu) and winxp but it's more convenient right now for me to use
the 98 laptop.