[Tutor] Summing up numbers in a file

[Adam Bark]

On 26/10/10 21:20, masawudu bature wrote:
> How do I sum all occurrences of  a number in a file?
> I have a file with a bunch of numbers, each on it's own line:
> 5
> 3
> 11
> 3
> 7
> 3
> 5
> 5
> 11
> 7
> 7
> ...
> How do i sum them up so that the output will be ,
> 5 :  15
> 3 :   9
> 11:  22
> 7 :   21
>
Assuming you know how to iterate through a file, you could try saving 
the number of occurrences of each number in the file into a dictionary.
Something like:

if num in my_dict:
     my_dict[num] += 1
else:
     my_dict[num] = 1

HTH.
Adam.
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