[Tutor] Counting the consistent rankings

[Emile van Sebille]

On 7/23/2012 2:11 PM Ali Torkamani said...
> Hi All,
>
> I want to count how many  (what percentage)  of partial orders are
> identical in two lists.

You may find SequenceMatcher from module difflib helpful.  See 
http://docs.python.org/library/difflib.html for info.

Emile




> (For example let L1 be the list of ground truth
> scores and L2 be the estimated scores for a list of students, I want to
> check how many (what percentage) of pairwise orderings (rankings) are
> preserved)
>
> I have written the following (inefficient) code, is there anyway in
> Python to write it more efficiently?
>
>
>      S=0;
>      A=0;
>      n=len(L1)
>      for i in range(n):
>          for j in range(i+1,n,1):
>              A+=1;
>              if (L1[i]>L1[j] and L2[i]>L2[j]) or (L1[i]<L1[j] and
> L2[i]<L2[j]) or (L1[i]==L1[j] and L2[i]==L2[j]):
>                  S+=1
>
>      print(100*float(S)/A)
>
>
> Thanks,
>
> A
>
>
>
> _______________________________________________
> Tutor maillist  -  Tutor at python.org
> To unsubscribe or change subscription options:
> http://mail.python.org/mailman/listinfo/tutor
>