class Solution:
    def simplifyPath(self, path):
        stack = []
        for index in range(len(path)):
            char = path[index]
            if stack:
                if char == "." and index != len(path)-1 and path[index+1] == char:
                    # Go back a dir, pop twice
                    stack.pop()
                    if stack:
                        stack.pop() # Always check for underflow while popping
                elif char == "/" and ((index != len(path)-1 and path[index+1] == char) or stack[-1] == char): 
                    # Simplify // to / by not pushing anything to stack
                    continue
            if char not in ["."]:
                # Ignore . and push char to stack
                stack.append(char)
        return "".join(stack).rstrip("/") if len(stack)>1 else "/" # read stack