parenthesis_checker.py

class Stack:
  def __ini__(self):
    self.array = []
  def push(self,item):
    self.array.append(itme)
  def pop(self):
    return self.array.pop()
  def isEmpty(self):
    return True if len(array) > 0 else False
  
def matches(last_item_in_stack,symbol):
  opens = "([{"
  closes = ")]}"
  return opens.index[last_item_in_stack] == closes.index(symbol]
                                                         
def parenthesis_checker(string):
  s = Stack()
  index = 0
  balanced = True
  
  while index < len(string) and balanced:
    symbol = string[index]
    
    if symbol in "([{":
       s.push(symbol)
    else:
      if s.isEmpty():
         balanced = False
      else:
        last_itme_in_stack = s.pop()
                                                         
        if not matches(last_itme_in_stack,symbol):
           balanced = False
    index += 1
   if balanced and s.isEmpty():
      return True
   else:
      return False