leetcode-71-简化路径

题目描述：

方法：

class Solution: 
    def simplifyPath(self, path: str) -> str: 
        stack = [] 
        path = path.split("/") 
        for item in path: 
            if item == "..": 
                if stack : 
                    stack.pop() 
            elif item and item != ".": 
                stack.append(item) 
        return "/" + "/".join(stack)