input: Write a function to determine if a string `s` has matching parentheses. If it is possible to match all parentheses '(' and ')' in the string, return True. Otherwise, return False.
  
  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("(())((()())())") == True
  assert matching_paren("((((((((") == False
  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