testing a sequence for 'identicalness'

[Tim Peters]

[Rajarshi Guha]
>   does anybody knwo how I can check a sequence for 'identical ness', ie
> given a sequence:
>
> [1,1,1,1,1,1,1,1,1,1]
>
> it would be classified as 100% identical

100% identical to what?  Itself?  That's easy <wink>.

> and
>
> [1,1,1,1,1,1,1,1,1,2]
>
> would be classified as 90% identical.

>>> import difflib
>>> m = difflib.SequenceMatcher(None, [1]*10, [1]*9 + [2])
>>> print m.ratio()
0.9
>>>

Read the difflib docs for more.