[LeetCode][Python3] 227. Basic Calculator II

Problem :

https://leetcode.com/problems/basic-calculator-ii/

My Solution :

class Solution:

def calculate(self, s: str) -> int:

s = s.replace(' ', '') + '+'

total = before = 0

sign = '+'

start = 0

for i in range(len(s)):

if s[i] in ('+', '-', '*', '/'):

num = int(s[start:i])

if sign == '+':

total += before

before = num

elif sign == '-':

total += before

before = -num

elif sign == '*':

before *= num

else:

before = int(before/num)

start = i+1

sign = s[i]

return total + before