def is_show_uncategorized(self, request):
        """Return the result of the "?show_uncategorized" query string param"""

        show_uncategorized = request.GET.get('show_uncategorized', False)
        if show_uncategorized is True or show_uncategorized == 'true':
            return True
        return False
def dfs(self,candidates,target,start,reslist):
        length = len(candidates)
        if target == 0: 
            return self.result.append(reslist)