[Zope] HOW TO COUNT VARIABLE WITH <DTML-IN>

[Tino Wildenhain]

Hi Mike,

--On Montag, 16. Dezember 2002 15:32 -0700 Mike Doanh Tran 
<mtran@shufflemasterrd.com> wrote:

>
> How do i count the value of a variable inside of <dtml-in>
> I want to count not just the occurence of the  variable but the
> value of that variable also. For Example i have a variable name "weight":
>
> <dtml-in getQuery>
>   <dtml-var count-weight>
> </dtml-in getQuery>
>
> <dtml-var count-weight> will give me a total number of occurence for the
> variable weight.  What i want to do is count the value of weight.
>
> if weight=1 then count how many 1 there are
> if weight=2 then count how many 2 there are
> and so on ....

While it is possible in DTML, I show you a solution with lesser pain:
Add a python script and use a construct like that:

weights={}
for line in context.getQuery():
    weights[line.weight]=weights.get(line.weight,0)+1

return weights


The script will start with an empty dictionary (hash, associative array)
and for any value of weight, it looks up the current value with this
kay in the dictionary, using 0 as default if none is found and adds 1
to it. In the result you have a dictionary which maps each value
for weight to the count of this value.

HTH
Tino Wildenhain