comparing lists

[Lulu of the Lotus-Eaters]

|[Paul Magwene]
|> If you know you're dealing with lists of strings why don't you use the
|> "join" methods in the string module.

"Mark McEahern" <marklists at mceahern.com> wrote previously:
|Thanks.  I hadn't thought of that.  Sadly, it won't work for me because as I
|said my comparison is order-insensitive whereas your approach is
|order-sensitive.

You can always sort the lists before joining them.  Or sort copies if
you need to leave the originals as-s.  I.e.

    ltmp = copy.copy(lst)
    ltmp.sort()
    ...

There was a flaw, however, with Magwene's suggestion.  Once you join the
items, you lose some information about what was where originally.  For
example:

    l1 = ['ab ','c',' d']
    l2 = ['ab',' c ','d']
    l3 = ['ab  c  d']

These will all compare as equal.  What you probably want to do is add a
delimiter between the elements that you are pretty sure will not occur
in the original strings, e.g.:

    >>> string.join(['a','b','c'],'$%^').upper()
    'A$%^B$%^C'

or,

    >>> '|-|'.join(['a','b','c']).upper()
    'A|-|B|-|C'


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