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A query about list

Mel Wilson mwilson at the-wire.com
Fri Oct 10 11:05:23 EDT 2003 
In article <slrnbobkr7.io6.ramen at lackingtalent.com>,
Dave Benjamin <ramen at lackingtalent.com> wrote:
>This *seems* to work, but I have a sneaking feeling there's a bug in here as
>a result of the slice assignment. I haven't been able to find a boundary
>case that breaks this, but it seems like the slice assignment would mess up
>the indexes in the loop. Can anyone find a way to either break or improve
>this?

It does or doesn't, depending on what you want:



def flatten (a):
    for i in xrange (len(a)-1, -1, -1):
        if type (a[i]) is type ([]):
            a[i:i+1] = a[i]


def deep_flatten (a):
    i = 0
    while i < len (a):
        if type (a[i]) is type ([]):
            a[i:i+1] = a[i]
        else:
            i += 1


if __name__ == '__main__':
    def test (xx):
        print xx
        x = xx[:]
        flatten (x);  print x
        x = xx[:]
        deep_flatten (x);   print x
        print

    test ([1,2, [3,4], 5, [], [6,7,8], 9])
    test ([1, [20,21], [30,[310,311],32], [], [4], 5])



        Regards.        Mel.
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