Python || Stack || Clean Solution
\nfrom collections import deque\nfrom typing import List\n\n\nclass Solution:\n    def calPoints(self, ops: List[str]) -> int:\n        stk = deque()\n\n       
```\nfrom collections import deque\nfrom typing import List\n\n\nclass Solution:\n    def calPoints(self, ops: List[str]) -> int:\n        stk = deque()\n\n        push, pop = stk.append, stk.pop\n\n        for e in ops:\n            if e == \'+\':\n                push(stk[-1] + stk[-2])\n            elif e == \'D\':\n                push(2 * stk[-1])\n            elif e == \'C\':\n                pop()\n            else:\n                push(int(e))\n\n        return sum(stk)\n```
['Stack', 'Python']