[Numpy-discussion] Count the occurrence of a certain integer in a list of integers

Keith Goodman kwgoodman@gmail....
Tue Aug 7 07:19:47 CDT 2007


On 8/7/07, Nils Wagner <nwagner@iam.uni-stuttgart.de> wrote:
> I have a list of integer numbers. The entries can vary between 0 and 19.
> How can I count the occurrence of any number. Consider
>
>  >>> data
> [9, 6, 9, 6, 7, 9, 9, 10, 7, 9, 9, 6, 7, 9, 8, 8, 11, 9, 6, 7, 10, 9, 7, 9, 7, 8, 9, 8, 7, 9]
>
>
> Is there a better way than using, e.g.
>
> >>> shape(where(array(data)==10))[1]
> 2
>
>
> to compute the occurrence of 10 in the list which is 2 in this case ?

Would list comprehension work?

len([z for z in data if z == 10])


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