# Python program to find the group sum till each K in a list

• Last Updated : 02 Dec, 2020

Given a List, the task is to write a Python program to perform grouping of sum till K occurs.

Examples:

Input : test_list = [2, 3, 5, 6, 2, 6, 8, 9, 4, 6, 1], K = 6
Output : [10, 6, 2, 6, 21, 6, 1]
Explanation : 2 + 3 + 5 = 10, grouped and cummulated before 6.

Input : test_list = [2, 3, 5, 6, 2, 6, 8], K = 6
Output : [10, 6, 2, 6, 8]
Explanation : 2 + 3 + 5 = 10, grouped and cummulated before 6.

Method : Using loop

In this, we maintain a sum counter, if K occurs the summation is appended to result list, along with K, else the summation counter is updated with current value.

## Python3

 `# Python3 code to demonstrate working of``# Group Sum till each K``# Using loop``from` `collections ``import` `defaultdict`` ` `# initializing list``test_list ``=` `[``2``, ``3``, ``5``, ``6``, ``2``, ``6``, ``8``, ``9``, ``4``, ``6``, ``1``]`` ` `# printing original lists``print``(``"The original list is : "` `+` `str``(test_list))`` ` `# initializing K``K ``=` `6`` ` `temp_sum ``=` `0``res ``=` `[]``for` `ele ``in` `test_list:``    ``if` `ele !``=` `K:``        ``temp_sum ``+``=` `ele`` ` `    ``# append and re initializing if K occurs``    ``else``:``        ``res.append(temp_sum)``        ``res.append(ele)``        ``temp_sum ``=` `0`` ` `res.append(temp_sum)`` ` `# printing result``print``(``"Computed list : "` `+` `str``(res))`

Output

```The original list is : [2, 3, 5, 6, 2, 6, 8, 9, 4, 6, 1]
Computed list : [10, 6, 2, 6, 21, 6, 1]```
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