Need Help sorting alphabetically.

[Greg Jorgensen]

"Remco Gerlich" <scarblac at pino.selwerd.nl> wrote in message
news:slrn93u8qc.5lh.scarblac at pino.selwerd.nl...
> Chris Arai <chris at araidesign.com> wrote in comp.lang.python:

> > I would like to sort alphabetically (I'm not sure that is the correct
> > term) so that strings of alpha numerics sort alphabetically instead of
> > by ASCII order.
[snip]
> It seems you want to ignore case and ignore everything outside a-z.
> So make a function that throws out all of the other characters and
> turns the rest into a single case, and then compares those:
>
> def compare_alphabetically(a, b):
>    a = filter(lambda x: x.isalpha(), a.upper())
>    b = filter(lambda x: x.isalpha(), b.upper())
>    return cmp(a,b)

The filter is unnecessary; the upper() and lower() methods of string only
change alphabetic characters. A simpler solution is:

def compare_alpha(a, b):
    return cmp(a.lower(), b.lower())
...
m.sort(compare_alpha)

or use a lambda:

m.sort(lambda a,b: cmp(a.lower(), b.lower()))

--
Greg Jorgensen
Deschooling Society
Portland, Oregon, USA
gregj at pobox.com