brackets problem

def isLeft(bracket):
  if bracket == "(":
    return True
  if bracket == "[":
    return True
  if bracket == "{":
    return True

  return False

def isPair(bracket2, bracket1):
  
  if bracket1 == '(' and bracket2 == ')':
    return True

  if bracket1 == '[' and bracket2 == ']':
    return True

  if bracket1 == '{' and bracket2 == '}':
    return True

def solution(a):

  stack = []

  for bracket in a:
    if len(stack) > 0 and isPair(bracket, stack[len(stack) - 1]):
      stack.pop()
    else:
      stack.append(bracket)

  if len(stack) == 0:
    return 1 # correct
  else:
    return 0 # wrong



if solution("[{}{}]") == 1:
  print('SUCCESS 1')

if solution("{[{}}]") == 0:
  print('SUCCESS 2')


if solution("[()]()]") == 0:
  print('SUCCESS 3')

if solution("[{()}]") == 1:
  print('SUCCESS 4')

if solution("][") == 0:
  print('SUCCESS 5')

if solution("()[]{}()[]{}") == 1:
  print('SUCCESS 6')