---> 17 elif d[char] == stack[-1]: TypeError: 'set' object is not subscriptable

wrote the same code but always getting and error

def balanced_stack(s):

stack = []

d = {'(',')',
         '[',']',
         '{','}' ,}

for char in s:

if not stack:
            stack.append(char)
            print('if not stack char = ', char)
        elif char not in d:
            stack.append(char)
            print('elif char not in d char = ', char)
        elif d[char] == stack[-1]:
            stack.pop()
            print('elif dchar stack char = ', char)
        else:
            stack.append(char)
            print('else char = ', char)

if not stack:
        return True
    else:
        return False