Balanced parenthesis

Question

Why it is wrong?This code is failing in test 3...
code is:

def balanced(expression):
list=[]
for item in expression:
if item=="(" or item==")":
if item=="(":
list.insert(0,item)
if "("in list and item==")":
list.pop(0)
if list==[]:
return True
else:
return False

print(balanced(input()))

Answer 1

Hadise, the following is a bit simpler and based on the observation that the stack of only "(" characters is nothing but a glorified counter.

def balanced(expression):
count = 0
for char in expression:
if char == "(":
count += 1
elif char == ")":
if count == 0:
return False
count -= 1
return count == 0

print(balanced(input()))

Answer 2

Well, I wrote this code and it was correct😉

def balanced(expression):
x=[]
for letter in expression:
if letter == "(":
x.insert(0,letter)
if letter ==")":
if x != []:
x.pop(0)
elif x==[]:
return False

if x==[]:
return True
else:
return False

print(balanced(input()))

Answer 3

)

That isn't balanced but your code will incorrectly say it is.

I don't know what test case 3 is but you should fix the above problem and see if your tests pass.

Answer 4

Oop, I must have accidentally deleted my post, but ya pretty much same as what Josh Greig said anyway.

Answer 5

Good job Josh Greig😀
Yeah, Your code is simpler than mine.😁
Thanks for your good suggestion.💫

Answer 6

Have you considered what will happen if there are more ")"s than "("s?