input: Write a function to identify if a string `s` has matching parentheses. The function should return `True` if all parentheses in the string are properly matched and `False` otherwise. If the string is empty, the function should return `True`.
  
  def matching_paren(s):
      stack = []
      for char in s:
          if char == '(':
              stack.append(char)
          elif char == ')':
              if len(stack) == 0:
                  return False 
              stack.pop()
      
      if len(stack) == 0:
          return True
      else:
          return False
  
  assert matching_paren("(())")==True
  assert matching_paren("(()")==False
  assert matching_paren("())")==False
  assert matching_paren("((()))")==True
  assert matching_paren("")==True
output: def matching_paren(s):
      stack = []
      for char in s:
          if char == '(':
              stack.append(char)
          elif char == ')':
              if len(stack) == 0:
                  return False 
              stack.pop()
      
      if len(stack) == 0:
          return True
      else:
          return False