[Tutor] recursive problem

[Shashwat Anand]

On Thu, Sep 9, 2010 at 2:21 PM, Roelof Wobben <rwobben at hotmail.com> wrote:

>  Hello,
>
> I have this :
>
> def recursive_count(target, nested_num_list):
>     """
>       >>> recursive_count(2, [2, 9, [2, 1, 13, 2], 8, [2, 6]])
>       4
>       >>> recursive_count(7, [[9, [7, 1, 13, 2], 8], [7, 6]])
>       2
>       >>> recursive_count(15, [[9, [7, 1, 13, 2], 8], [2, 6]])
>       0
>       >>> recursive_count(5, [[5, [5, [1, 5], 5], 5], [5, 6]])
>       6
>     """
>     for element in nested_num_list:
>         if type(element) == type([]):
>            test = recursive_count(target, element)
>         print element, target
>         if element == target :
>            count = count + 1
>     return count
>
> if __name__ == "__main__":
>     import doctest
>     doctest.testmod()
>
>
> Now I get this message :
>
> UnboundLocalError: local variable 'count' referenced before assignment
>

It is because you are doing count = count + 1
But where is count defined.


>
> But if I do this :
>
> def recursive_count(target, nested_num_list):
>     """
>       >>> recursive_count(2, [2, 9, [2, 1, 13, 2], 8, [2, 6]])
>       4
>       >>> recursive_count(7, [[9, [7, 1, 13, 2], 8], [7, 6]])
>       2
>       >>> recursive_count(15, [[9, [7, 1, 13, 2], 8], [2, 6]])
>       0
>       >>> recursive_count(5, [[5, [5, [1, 5], 5], 5], [5, 6]])
>       6
>     """
>   count = 0
>   for element in nested_num_list:
>         if type(element) == type([]):
>            test = recursive_count(target, element)
>         print element, target
>         if element == target :
>            count = count + 1
>     return count
>
> if __name__ == "__main__":
>     import doctest
>     doctest.testmod()
>
> The count will always be 0 if a nested list is being found.
>
> What's the python way to solve this
>

I am not sure what do you want to achieve by this ?
What is the problem statement ?


>
> Roelof
>
>
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-- 
~l0nwlf
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