[Numpy-discussion] ndarray.count() ?

[Sasha]

On 9/7/06, Martin Spacek <scipy at mspacek.mm.st> wrote:
> What's the most straightforward way to count, say, the number of 1s or
> Trues in the array? Or the number of any integer?
>
> I was surprised to discover recently that there isn't a count() method
> as there is for Python lists. Sorry if this has been discussed already,
> but I'm wondering if there's a reason for its absence.
>

You don't really need count with ndarrays:

>>> from numpy import *
>>> a = array([1,2,3,1,2,3,1,2])
>>> (a==3).sum()
2