Steve R. Hastings wrote:
> You could also use a function that counts all different values in a list,
> reducing the list to a dictionary whose keys are the unique values from
> the list. I got the idea from a discussion here on comp.lang.python; I
> called my version of it tally().
>
> d = tally(bool(x) for x in seq)
> print d[True] # prints how many true values in seq
> print d[False] # prints how many false values in seq
>
>
> tally() is in my iterwrap.py module, which you can get here:
>
> http://home.blarg.net/~steveha/iterwrap.tar.gz
>
>>> from itertools import groupby
>>> tally = lambda it : dict((x,sum(1 for _ in y)) for x,y in
>>> groupby(sorted(it)))
>>> tally('abbcabbcca')
{'a': 3, 'c': 3, 'b': 4}
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