프로그래머스 - 수식 최대화 (L2)

 1from itertools import permutations
 2def solution(expression):
 3    answer = 0
 4    operations = list(filter(lambda x: not x.isdigit(), expression))
 5    numbers = expression.replace('-','+').replace('*','+').split('+')
 6    expression = [int(numbers[0])]
 7
 8    for i in range(len(operations)):
 9        expression.append(operations[i])
10        expression.append(int(numbers[i+1]))
11
12    for case in permutations(('+', '-', '*'), 3):
13        temp = expression[::-1]
14        for op in case:
15            stack = []
16            while temp:
17                if temp[-1] == op:
18                    temp.pop()
19                    a = stack.pop()
20                    b = temp.pop()
21                    stack.append(eval(str(a)+op+str(b)))
22                else:
23                    stack.append(temp.pop())
24            temp = stack[::-1]
25        answer = max(answer, abs(temp[0]))
26    return answer