input: 
  def matching_parentheses(s: str) -> bool:
      """ Check if the string has matching parentheses.
      >>> matching_parentheses("(())")
      True
      >>> matching_parentheses("(()")
      False
      """
      stack = []
      for char in s:
          if char == '(':
              stack.append(char)
          elif char == ')':
              if len(stack) == 0:
                  return False
              stack.pop()
      
      return len(stack) == 0
  
output:     stack = []
      for char in s:
          if char == '(':
              stack.append(char)
          elif char == ')':
              if len(stack) == 0:
                  return False
              stack.pop()
      
      return len(stack) == 0