code: def simplify_path(path):
      
      skip = {'..', '.', ''}
      stack = []
      paths = path.split('/')
      for tok in paths:
          if tok == '..':
              if stack:
                  stack.pop()
          elif tok not in skip:
              stack.append(tok)
      return '/' + '/'.join(stack)
docs: :type path: str
      :rtype: str