Balanced Parantheses - Python Data Strcutures

Question

Hi,
My code is failing Test Case #3 and Test Case #7, can someone help why? I have tried a lot but can't seem to figure out what's going wrong. Any help will be highly appreciated.
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):
#your code goes here
x=Stack()
for i in expression:
if i=='(':
x.push(i)
elif i==')':
x.pop()
return x.is_empty()
print(balanced(input()))

Answer 1

# simple fix:
def balanced(expression):
#your code goes here
x=Stack()
for i in expression: 7
if i=='(':
x.push(i)
elif i==')':
if x.is_empty(): return False
else: x.pop()
return x.is_empty()

Answer 2

you posted twice the same thread/question:
https://www.sololearn.com/Discuss/2821562/?ref=app
https://www.sololearn.com/Discuss/2821561/?ref=app

Answer 3

your code throw error if stack is empty and closing parenthesis is encountered (try to pop empty items list ^^)

Answer 4

https://code.sololearn.com/ceWOKlkt07Dg/?ref=app