#elements of seq A in seq B

Neal Becker ndbecker2 at gmail.com
Thu Aug 20 13:01:29 CEST 2009


Jan Kaliszewski wrote:

> 20-08-2009 o 01:19:24 Neal Becker <ndbecker2 at gmail.com> wrote:
> 
>> What would be a time efficient way to count the number of occurrences of
>> elements of sequence A in sequence B?  (in this particular case, these
>> sequences are strings, if that matters).
> 
> If you mean: to count occurences of each element of A (separately) in B...
> 
> Hm, maybe something like this:
> 
>    # result as a dict {<element of A>: <how many occurences in B>, ...}
>    dict((element, B.count(element)) for element in A)
> 
> 
> If you mean: to count non overlaping occurences of string A in B
> -- simply:
> 
>    B.count(A)
> 
> 
> Regards,
> *j
> 

I meant #occurrences of characters from the set A in string B




More information about the Python-list mailing list