71. 简化路径

71. 简化路径
#核心思想:栈
#依据题意 ..不需要出栈，其余入栈
class Solution:
    def simplifyPath(self, path: str) -> str:
        stack = []
        for p in path.split('/'): #以'/'分割
            if stack and p == '..':
                stack.pop()
            elif p not in " ..":
                stack.append(p)
        return '/' + '/'.join(stack) #均以'/'开头