evalute_reverse_polish_notation.py

class Solution:
    def evalRPN(self, tokens: list[str]) -> int:
        stack = []

        for t in tokens:
            if t not in '/+-*':
                stack.append(int(t))

            else:
                num = stack.pop()
                if t == '+':
                    stack[-1] += num
                elif t == '-':
                    stack[-1] -= num
                elif t == '*':
                    stack[-1] *= num
                else:
                    stack[-1] = int(stack[-1] / num)

        return stack[0]