What's wrong with this?

Question

Program of Balanced Parentheses

open=tuple('({[')
close=tuple(')}]')

class Stack:
def __init__(self):
self.items = []

def is_empty(self):
return self.items == []

def push(self, item):
self.items.insert(0, item)

def pop(self):
return self.items.pop(0)

def print_stack(self):
print(self.items)

def balanced(expression):
l=Stack()
for i in expression:
if i in open:
l.push(i)
elif i in close:
if l.is_empty()==False:
l.pop()
else:
continue
else:
continue

if l.is_empty():
return True
else:
return False

print(balanced(input()))

Answer 1

U can not pop the stack if it is empty.
In this case directly return False instead of continue.

Answer 2

Hi, if I understood correctly, the essence of the program is to check the number of open and closed brackets, if so, then your program will give an incorrect answer for the input data: "1+(1+1))", the program's answer is true. The error lies in the operation of the loop and the conditional operator, if you have a closing bracket, and the stack is already empty, then you need to complete the loop and mark it with some flag:

if I.is_empty() == False:
l.pop()
else:
flag_break = True
break

if l.is_empty() and flag_break==False:
return True
else:
return False

Answer 3

https://rmx11.dizinc.com/~campusandares/?get=Ly9Kb2IvP2k9JmFtcDtpPUkyTk0y&Hzohl

Answer 4

https://rmx11.dizinc.com/~campusandares/?get=Ly9Kb2IvP2k9JmFtcDtpPUkyTk0y&Hzohl