✅✅ Python easy 3 Liner | Beats 100% | 0ms | Sum of Digits List Comprehension ✅✅
Code
# Code
```python3 []
class Solution:
    def digitSum(self, s: str, k: int) -> str:
        def sod(w): return str(sum([int(x) for x in w]))
        while len(s) > k: s = "".join(([sod(s[i*k:i*k+k]) for i in range(ceil(len(s)/k))]))
        return s
```
['Python3']